Tag: Arizona

Arizona, located in the southwestern region of the United States, is renowned for its diverse landscapes and cultural richness. Home to iconic natural wonders such as the Grand Canyon, Monument Valley, and the red rocks of Sedona, Arizona offers a dramatic and varied terrain that ranges from arid deserts to pine-covered mountains. The state’s climate is typically characterized by hot summers and mild winters, with the southern parts being desert-like while the northern regions experience a more temperate climate. Arizona is also rich in Native American history, with numerous tribes such as the Navajo, Hopi, and Apache having deep roots in the region. The state’s cities, including Phoenix and Tucson, blend modern urban life with a strong appreciation for the natural environment and cultural heritage. Arizona’s economy thrives on tourism, technology, and agriculture, making it a dynamic and multifaceted state.

Wolf Hole – Mohave County Ghost Town

Posted on by
Mohave County, Arizona Ghost Towns
Mohave County, Arizona Ghost Towns

Wolf Hole, Arizona is a ghost town in the remote Arizona Strip region of Mohave County, northwestern Arizona. It sits on the Uinkaret Plateau (near Wolf Hole Mountain) at approximately 36°45′46″N 113°32′58″W, at an elevation of about 5,043 feet (1,537 m). The site lies roughly 25–33 miles south of St. George, Utah, in a sparsely populated area of plateaus, canyons, and limited water sources north of the Grand Canyon.

Today it consists mainly of foundations, a derelict (often described as adobe) house, and remnants of fencing or corrals. Access is via graded dirt roads (generally suitable for 2WD vehicles in good weather), and the surrounding landscape includes areas near the Mount Trumbull Wilderness.

Naming and Early Exploration

The name “Wolf Hole” stems from a mistranslation by Major John Wesley Powell during his Colorado River and Arizona Strip explorations in the late 1860s–1870s. Powell and his party applied the name to a local spring and water hole; the Paiute (Pah-Ute) term was reportedly something like Shinabitz-spitz or a reference to “Coyote Spring.” Explorers conflated the animal name, and “Wolf Hole” stuck on maps and in records.

The spring was a critical water source in an arid landscape, supporting Indigenous use and later Euro-American ranching. Powell’s broader mapping and ethnographic work helped open the region to further exploration and settlement.

Ranching History and Settlement

The Arizona Strip’s harsh conditions—limited water, droughts, isolation, and rugged terrain—delayed permanent settlement. Early livestock activity intensified in the late 19th century amid the broader Western cattle boom. By the 1890s, prominent cattleman Preston Nutter expanded operations across the Arizona Strip (and into Utah and Colorado). Around 1897 he acquired rights around Wolf Hole (including purchase of a spring claim for a modest sum) as part of consolidating water sources and range rights on the Shivwits Plateau and nearby areas such as Grand Wash and Mount Trumbull. Nutter became one of the dominant figures controlling springs and grazing lands in the western Strip.

Smaller ranchers and homesteaders also operated in the vicinity, practicing open-range cattle and some sheep raising, with limited farming where water allowed. Droughts (including severe ones in the early 1890s and later periods) repeatedly stressed operations. The 1916 Stock-Raising Homestead Act and related land policies encouraged further small-scale claims, but the environment limited long-term success.

The Community and Post Office Era (1918–1927)

Wolf Hole formalized as a small ranching and farming outpost in 1918 with the opening of a U.S. post office (sources note establishment around July 3, 1918; some variation exists for exact start/end years, commonly cited as 1918–1927). Dexter Parker served as postmaster and operated the facility from his ranch, which also functioned in part as a general store, gas station, and stop for travelers. The post office linked isolated ranchers and homesteaders to the outside world (often via routes to St. George, Utah), handling mail, supplies, and sometimes dairy products from local operations.

The settlement remained minimal—likely fewer than a dozen households clustered near the spring and rudimentary ranch buildings. It never developed into a substantial town with commercial or mining focus (unlike many Mohave County boom towns driven by minerals). Daily life centered on livestock, water management, and coping with isolation, extreme weather, and scarce resources.

Decline and Abandonment

The post office closed in 1927, marking the effective end of the formal community. Factors included the region’s inherent challenges (chronic water scarcity, drought, limited economic viability for small operators), consolidation of ranching under larger outfits, and broader shifts in Western land use and transportation. Residents dispersed to more accessible areas. By the mid-20th century the site was largely abandoned, with structures deteriorating into the sparse remains visible today.

Cultural Notes and Legacy

American author and environmentalist Edward Abbey (1927–1989), known for Desert Solitaire and The Monkey Wrench Gang, sometimes claimed Wolf Hole as a residence or used it as a mailing address/byline. This was largely symbolic or aspirational, reflecting his affinity for remote Southwest wilderness; he did not maintain permanent residence there (accounts describe it as “camouflage” enhancing his desert hermit persona). Visitors seeking him in the 1970s found little or nothing at the site.

Wolf Hole exemplifies the ephemeral nature of many Arizona Strip outposts: water-dependent ranching communities that briefly served isolated settlers before fading. It contrasts with Mohave County’s earlier mining boom towns and stands as a quiet remnant of frontier adaptation to one of Arizona’s most remote landscapes. Nearby features include Wolf Hole Mountain and ongoing land management activities (e.g., Bureau of Land Management projects related to fuels reduction and habitat in the broader Wolfhole area).

Sources for this report draw primarily from historical summaries, ghost town documentation, USGS geographic data, ranching histories of the Arizona Strip (including Nutter’s operations), and contemporary accounts of the site and its cultural associations. Primary records on such remote places are limited, and some details (exact post office dates, precise population) vary slightly across sources.

Glen Canyon Dam

Posted on by

Glen Canyon Dam is a concrete arch-gravity dam on the Colorado River in northern Arizona, near the town of Page (about 15 miles upstream from Lees Ferry and roughly 8 miles south of the Utah-Arizona border). It stands 710 feet high above bedrock (583 feet above the original riverbed), with a crest length of 1,560 feet. It forms Lake Powell, one of the largest reservoirs in the United States (capacity roughly 24–27 million acre-feet at full pool of about 3,700 feet elevation). The dam is a key unit of the Colorado River Storage Project (CRSP).

Glen Canyon Dam, Page, Arizona. Photo by James L Rathbun
Glen Canyon Dam, Page, Arizona. Photo by James L Rathbun

Origins and Why It Was Built

Interest in a dam in Glen Canyon dates to the early 20th century. U.S. Geological Survey hydrologist E.C. LaRue proposed a site as early as 1916–1921, initially more for flood control than long-term storage. Studies continued in the 1920s, but priority went to Hoover Dam (completed 1936) farther downstream.

The decisive driver was the 1922 Colorado River Compact, which apportioned the river’s waters roughly equally between the Upper Basin (Colorado, Utah, Wyoming, New Mexico) and Lower Basin (California, Arizona, Nevada), with measurement at Lees Ferry. The Upper Basin states needed large upstream storage to develop their share for irrigation, municipal, and industrial use without risking failure to meet delivery obligations to the Lower Basin during droughts. Without storage, Upper Basin development would be constrained because water would simply flow downstream to Hoover Dam/Lake Mead.

By the 1940s–1950s, rapid population and economic growth in the West intensified the need. The Bureau of Reclamation advanced the Colorado River Storage Project, a system of dams and reservoirs to regulate flow, store water for beneficial use, provide flood control, reclaim arid lands, and generate hydropower. Hydropower revenues were essential: they would repay construction costs and help finance other Upper Basin projects. Glen Canyon Dam was the centerpiece—the largest storage feature—providing the bulk of the system’s capacity to hold water during wet years for release in dry ones while guaranteeing Lower Basin deliveries.

Congress authorized the CRSP (including Glen Canyon Dam) on April 11, 1956. The project was never primarily a local irrigation scheme; its core purposes were basin-wide storage and power generation.

Site Selection

Engineers and geologists evaluated multiple sites in lower Glen Canyon from the 1920s through the late 1940s (intensive work 1946–1948). Key criteria included:

  • A large reservoir basin capable of holding an immense volume of water.
  • Strong, stable canyon walls and bedrock foundation able to support a high dam.
  • Proximity to quality aggregate (rock and sand) for concrete—available nearby on Wahweap Creek.
  • Economic feasibility and constructability.

An early favored site was about 4 miles upstream from Lees Ferry (which could have held more water), but the chosen site—roughly 15–16.5 miles upstream—was selected for superior foundation rock (Navajo Sandstone cliffs rising nearly vertically) and easier access to gravel deposits. The remote location presented challenges: no nearby rail, and a 200-mile drive to cross from one rim to the other. This necessitated new access roads and the Glen Canyon Bridge (a 1,271-foot steel-arch bridge completed 1959, then among the world’s highest).

The final site sits in a narrow gorge of sandstone and shale, ideal for an arch-gravity design that transfers load into the abutments.

Construction and Filling

Construction began almost immediately after authorization. On October 15, 1956, President Dwight D. Eisenhower triggered the first blast by remote control from the White House. The prime contract went to Merritt-Chapman & Scott in April 1957 (winning bid about $108 million). Work included diversion tunnels to reroute the river, deep excavation to bedrock (about 137 feet), and shaping the canyon walls.

Concrete placement started in June 1960 (first formal pour around June 16–17) and continued around the clock. The dam contains roughly 4.9 million cubic yards of concrete in the structure itself (over 5.3 million including the powerplant)—enough for a multi-lane highway from Phoenix to Chicago. It was built in large blocks and topped out on September 13, 1963, at 710 feet. About 18 workers died during construction. The remote site required creating the town of Page, Arizona, for the workforce.

The river was diverted; the last diversion tunnel was closed on March 13, 1963, and Lake Powell began filling. First power generation occurred in September 1964. First Lady Lady Bird Johnson dedicated the dam on September 22, 1966. Filling to capacity took until June 22, 1980 (about 17 years). Glen Canyon National Recreation Area was established in 1972.

Controversy

The dam was highly controversial. Early CRSP plans included dams at Echo Park and Split Mountain in Dinosaur National Monument. A major campaign by the Sierra Club (led by David Brower), Wilderness Society, and others successfully blocked those, framing them as a threat to national parks. In the political compromise, Glen Canyon Dam proceeded (and was made larger to compensate for lost storage). Many environmentalists later regretted the trade-off, viewing the flooding of Glen Canyon’s scenic, archaeological, and ecological treasures as a major loss—“the place no one knew.” Archaeological salvage projects documented sites before inundation. The dam also fundamentally altered the Colorado River’s flow, temperature, and sediment regime through the Grand Canyon, leading later to the 1992 Grand Canyon Protection Act and adaptive management programs.

Operations and Later History

Lake Powell stores water for Upper Basin use and regulated releases to the Lower Basin. The powerplant (eight generators, original rating ~1,320 MW) has produced billions of kilowatt-hours annually in good years, with revenues supporting CRSP operations, environmental programs, and repayment. Notable events include 1983 floods that damaged the spillways (requiring major repairs) and ongoing adaptive management for downstream ecosystems and recreation.

Current Struggles with Low Water

Prolonged drought, aridification linked to climate change (warmer temperatures, reduced snowpack efficiency, higher evaporation and soil absorption), and overallocation have sharply reduced inflows. Lake Powell has declined dramatically from full-pool levels last seen in the early 1980s.

As of late August 2026, the lake has set new record lows, hovering around 3,518 feet elevation—roughly 22–23% of live capacity and about 180+ feet below full pool. It sits only tens of feet above minimum power pool (3,490 feet), the level at which the penstocks lose adequate submergence and the turbines can no longer generate hydropower reliably. Dead pool (the point at which water can no longer be released by gravity through the outlets) is at approximately 3,370 feet.

Projections in 2026 have warned of potential drops toward or below minimum power pool in 2027 under continued dry conditions, with reduced generation already occurring (output has fallen substantially from historical peaks). Managers have implemented emergency measures: reduced releases from Glen Canyon, increased upstream releases (e.g., from Flaming Gorge), and operational adjustments under drought contingency plans and interim guidelines to protect elevations near or above ~3,500–3,525 feet. Below minimum power pool, releases shift solely to the smaller river outlet works (not designed for sustained primary use), raising concerns about capacity, reliability, sediment, and downstream water delivery. Recreation (marinas, boat ramps) has been heavily impacted, with many facilities unusable.

The situation threatens hydropower for roughly millions of customers in the West, water supplies for agriculture and cities in the Lower Basin, and the broader Colorado River system’s stability. It has prompted study of potential dam modifications for lower-level operations and underscores the original assumptions about hydrology that no longer fully hold. Lake Powell and Lake Mead together hold far less water than in earlier decades, highlighting the ongoing Colorado River crisis.

In summary, Glen Canyon Dam was engineered as a linchpin of 20th-century Western water development—securing Upper Basin rights, enabling growth, and generating power—chosen for its geology and storage potential after careful evaluation. Decades later, it faces the limits of that vision under a drier climate and strained allocation system.

Hoover Dam

Posted on by

Hoover Damn Bypass seen from the top with Hoover Damn. Photo by James L Rathbun
Hoover Damn Bypass seen from the top with Hoover Damn. Photo by James L Rathbun

Hoover Dam (originally authorized as Boulder Dam or the Boulder Canyon Project) is a concrete arch-gravity dam in Black Canyon on the Colorado River, on the Arizona–Nevada border about 30 miles southeast of Las Vegas. Built between 1931 and 1936 during the Great Depression, it stands 726.4 feet high, stretches 1,244 feet along its crest, is 660 feet thick at the base and 45 feet at the crest, and contains about 3.25 million cubic yards of concrete (roughly 4.4 million cubic yards including appurtenant works). It creates Lake Mead, one of the largest reservoirs in the United States by capacity (historically around 28–32 million acre-feet depending on sedimentation surveys and measurement basis).

Why It Was Built

Hoover Dam takes shape from the concrete columns in which it was poured (shot from cableway control tower downstream on Nevada rim, so looking upstream)
Hoover Dam takes shape from the concrete columns in which it was poured (shot from cableway control tower downstream on Nevada rim, so looking upstream)

In the early 20th century, the Colorado River was both a vital resource and a destructive force for the arid Southwest. Seasonal floods devastated farmland (most dramatically in 1905–1907, when the river broke through irrigation canals and created the Salton Sea in California’s Imperial Valley), while dry periods left water supplies unreliable. Growing cities such as Los Angeles needed dependable municipal water, and the region sought hydroelectric power to support development.

The U.S. Bureau of Reclamation (then the Reclamation Service) saw a large multipurpose dam as the solution: flood control, irrigation water storage and delivery (including via the later All-American Canal to the Imperial and Coachella Valleys), municipal supply, river regulation, and hydropower. Power sales were intended to make the project self-supporting by repaying construction costs. Early advocates included Arthur Powell Davis of the Reclamation Service. Herbert Hoover, as Secretary of Commerce, strongly supported the project and helped resolve interstate water disputes.

A major political obstacle was allocating the river’s water among the seven basin states (Wyoming, Colorado, Utah, New Mexico, Arizona, Nevada, and California). Upper Basin states feared Lower Basin (especially California) development would claim most of the water under prior-appropriation rules. In 1922, Hoover chaired negotiations that produced the Colorado River Compact. It divided the basin at Lee Ferry, Arizona, allocating 7.5 million acre-feet annually to each basin (with the Lower Basin allowed an additional 1 million acre-feet under certain conditions) and requiring the Upper Basin not to deplete flows at Lee Ferry below 75 million acre-feet over any 10-year period. Arizona initially refused to ratify; the Compact became effective after six states approved it.

Photograph of the Hoover Dam (formerly Boulder Dam) from Across the Colorado River; From the series Ansel Adams Photographs of National Parks and Monuments, compiled 1941 - 1942, documenting the period ca. 1933 - 1942
Photograph of the Hoover Dam (formerly Boulder Dam) from Across the Colorado River; From the series Ansel Adams Photographs of National Parks and Monuments, compiled 1941 – 1942, documenting the period ca. 1933 – 1942

Congress authorized the project via the Boulder Canyon Project Act, signed by President Calvin Coolidge on December 21, 1928. The Act ratified the Compact (with California limited to 4.4 million acre-feet of the Lower Basin share), authorized the dam and related works (including the All-American Canal), and apportioned Lower Basin water roughly as California 4.4 million acre-feet, Arizona 2.8 million, and Nevada 0.3 million. President Hoover proclaimed the Compact effective in 1929. A later 1944 treaty allocated 1.5 million acre-feet annually to Mexico.

How the Site Was Chosen

Surveys of potential dam sites along the lower Colorado began in the early 1900s. The 1922 Fall-Davis Report recommended a high dam “at or near Boulder Canyon.” Boulder Canyon sites offered strong granite foundations but presented problems: one was crossed by a geologic fault; others were too narrow for construction camps or spillways; accessibility was poorer; and depth to bedrock was greater in places.

Further investigations (including the Weymouth Report) compared Boulder and nearby Black Canyon (about 20 miles downstream). Black Canyon was selected primarily for practical advantages: greater accessibility (a railroad spur could more easily connect from Las Vegas), shallower depth to solid bedrock in key locations, a narrower gorge with steeper walls, lower construction cost for a given height, and somewhat greater reservoir capacity for the same dam height. Geologic conditions were judged adequate (though Boulder’s granite was sometimes rated superior for load-bearing). The project retained the “Boulder Canyon” name even after the site shift. An independent Colorado River Board later confirmed the upper Black Canyon site.

The design chosen was a massive concrete arch-gravity dam (convex upstream face), developed under Bureau engineer John L. Savage and others. It transfers water pressure into the canyon walls while relying on its own weight for stability—an ultra-conservative approach after the 1928 St. Francis Dam failure raised safety concerns.

Construction

Six Companies, Inc. (a joint venture of major contractors including Utah Construction, Bechtel, Kaiser, Morrison-Knudsen, and others) won the contract in March 1931 with a bid of about $48.9 million—the largest U.S. government construction contract to that point. Work began in the spring of 1931 under Bureau construction engineer Walker Young and Six Companies superintendent Frank Crowe.

Key challenges included extreme desert heat, isolation, and the need to divert the entire river. Workers blasted four massive diversion tunnels (two on each side of the river, roughly 56 feet in diameter and totaling several miles in length) through the canyon walls. The river was diverted in November 1932. Cofferdams protected the site; the riverbed was excavated to solid rock; and canyon walls were scaled of loose rock. Concrete placement began June 6, 1933, and the last dam concrete was poured May 29, 1935. Cooling pipes embedded in the concrete controlled the heat of hydration so the massive structure would not crack. The dam began impounding water in February 1935, forming Lake Mead. Power generation started in late 1936. The project finished more than two years ahead of the seven-year contract schedule and was dedicated by President Franklin D. Roosevelt on September 30, 1935.

Roughly 21,000 people worked on the project at various times (peak employment over 5,000). Conditions were harsh; official figures record around 96–112 worker deaths from construction accidents (the exact total varies by counting method and whether indirect causes are included). Boulder City was built as a planned community for workers and their families. The dam was initially called Hoover Dam by the Hoover administration, renamed Boulder Dam under Roosevelt, and officially restored as Hoover Dam by Congress in 1947.

The Hoover Damn Bypass Bridge viewed from the Colorado River - Photo by James L Rathbun
The Hoover Damn Bypass Bridge viewed from the Colorado River – Photo by James L Rathbun

Hydropower revenues repaid the federal construction costs decades later. The powerplant (nameplate capacity roughly 2,080 MW after later uprates, with 17 main turbines) has historically supplied electricity to utilities in Arizona, Nevada, and California.

Current Struggles with Low Water

Lake Mead and the broader Colorado River system have been under severe stress from a multi-decade megadrought (intensified by climate change, higher temperatures, and increased evaporation), combined with chronic overuse relative to long-term average flows. The original Compact allocations assumed higher average river flows (around 16–17+ million acre-feet) than the observed long-term average (closer to 14–15 million acre-feet, and significantly lower in recent decades).

As of late August 2026, Lake Mead stood near record-low elevations for the modern period—approximately 1,038.87 feet, about 26% full (storage roughly 6.9 million acre-feet on a ~26 million acre-feet capacity basis used in some daily reporting). This is well below the full-pool elevation of about 1,220 feet and marks new lows relative to recent historical records (surpassing previous lows from 2022 in some metrics). Levels have continued a multi-year decline, with further drops expected until the next major snowmelt runoff.

Low water reduces hydropower generation because lower “head” (water pressure/height above the turbines) decreases output. Capacity falls sharply at lower elevations; generation has already been substantially reduced from historical averages, with further declines projected. Minimum power pool is around 950 feet (with some older turbines limited higher); dead pool (where water can no longer pass the dam by gravity) is about 895 feet. The reservoir remains above these critical thresholds but with a narrowing buffer.

Shortage declarations under existing guidelines have already triggered cuts in Lower Basin deliveries. Federal operating guidelines for 2027–2028 and the post-2026 framework emphasize protecting critical elevations at both Lake Mead and upstream Lake Powell (itself also near or at record lows). Measures include reduced releases from Powell to protect its infrastructure and power generation, mandatory and voluntary reductions in Lower Basin consumptive use (on the order of 1.25 million acre-feet annually plus additional conservation in early years of the new guidelines), and efforts to balance the system. Arizona faces particularly large percentage cuts under priority-based shortage sharing. Power production at Hoover is expected to remain constrained, raising costs for replacement energy and affecting ratepayers.

These challenges highlight the tension between the river’s engineered development (which enabled vast agricultural and urban growth in the Southwest) and the physical limits of a variable, arid basin under climate pressure. Ongoing negotiations among the basin states, tribes, Mexico, and the federal government focus on reducing overall use to match available supply while protecting critical infrastructure and ecosystems.

Hoover Dam remains an engineering landmark, a National Historic Landmark, and a major tourist destination, while continuing to serve its original purposes of flood control, water storage, and power generation—albeit under increasingly constrained hydrologic conditions.

Arthur Powell Davis

Posted on by
Arthur Powell Davis (February 9, 1861 – August 7, 1933)
Arthur Powell Davis (February 9, 1861 – August 7, 1933)

Arthur Powell Davis (February 9, 1861 – August 7, 1933) was an American civil engineer, hydrographer, topographer, and geographer who played a pivotal role in the early 20th-century development of water resources in the American West. As Director of the U.S. Reclamation Service (predecessor to the Bureau of Reclamation) from 1914 to 1923, he was a leading architect of comprehensive federal plans to control and develop the Colorado River. He is widely regarded as a key conceptual founder of the Boulder Canyon Project (which produced Hoover Dam) and broader multipurpose river-basin development.

Early Life and Education

Davis was born on a farm near Decatur, Illinois, the nephew of the famed explorer and geologist John Wesley Powell (leader of the 1869 Colorado River expedition through the Grand Canyon). His family connections and early exposure to the West shaped his career. He attended local schools and Kansas State Normal School before earning a Bachelor of Science degree in civil engineering from Columbian University (now George Washington University) in Washington, D.C., in 1888.

He married Elizabeth (Preston/Brown) Davis in 1888; they had several daughters. He co-founded the National Geographic Society in 1888 and later held leadership roles in engineering societies. He was elected to the American Academy of Arts and Sciences (1921) and the American Philosophical Society (1927).

Early Career with the U.S. Geological Survey

Through his uncle’s influence, Davis joined the U.S. Geological Survey (USGS) as an assistant topographer around 1882–1884. He worked extensively in the Rocky Mountain region and the Southwest (New Mexico, Arizona, and California), gaining firsthand knowledge of arid lands and the Colorado River Basin. He advanced to topographer and, by 1895, to hydrographer in charge of government stream measurements.

His early international work included hydrographic examinations of potential Nicaragua and Panama Canal routes (late 1890s–early 1900s). He later consulted on irrigation and flood control in Puerto Rico, China, Turkestan (under both Tsarist and Soviet governments), and other regions, and contributed to Panama Canal studies.

Leadership in the Reclamation Service

Davis joined the newly created Reclamation Service (established under the 1902 Reclamation Act) early in its history. He rose to Chief Engineer around 1906–1908 and was appointed Director on December 10, 1914, succeeding Frederick Haynes Newell. He held the post until the agency’s name changed to the Bureau of Reclamation on June 18, 1923; he retired the next day.

Under his leadership the Service built major irrigation and storage works, including the Roosevelt Dam (Salt River), Shoshone and Arrowrock dams (each the world’s tallest at the time of completion), Elephant Butte Dam (Rio Grande), the Gunnison Tunnel, and the Strawberry Tunnel. He was among the first to strongly advocate multipurpose dams in which hydroelectric power generation would help amortize overall project costs—a principle that became central to later federal water development.

Role in Controlling and Developing the Colorado River

Davis’s most enduring contribution was his long-term vision for the Colorado River. Influenced by his uncle’s explorations and his own surveys, he recognized the river’s interstate and international character (flowing through seven U.S. states and into Mexico) and argued that only the federal government could coordinate its development at the necessary scale.

As early as 1902 he publicly called for the “gradual comprehensive development of the Colorado River by a series of large storage reservoirs,” with a high dam on the lower river as the keystone. He promoted basin-wide planning for flood control, irrigation storage, domestic water supply, and power generation rather than fragmented local projects.

In 1922, during his directorship, the Reclamation Service produced the influential report Problems of Imperial Valley and Vicinity (Senate Document 142, 67th Congress), commonly known as the Fall-Davis Report (after Interior Secretary Albert B. Fall and Davis). It examined reservoir sites, justified a high dam in the Boulder Canyon area, analyzed water supply and needs, and provided foundational data used by the Colorado River Compact Commission. The report and Davis’s advocacy helped frame the river’s problems as national in scope and laid groundwork for the Boulder Canyon Project Act and construction of Hoover (originally Boulder) Dam. Contemporaries, including engineers involved in the project, later called him the “father of the Boulder Canyon Project.”

Davis opposed purely local or piecemeal schemes (such as an early standalone All-American Canal proposal) when they conflicted with a coordinated multipurpose federal plan. His emphasis on power revenues to support large storage dams helped make ambitious Colorado River projects financially and politically viable. Shortly before his death he was appointed consulting engineer on the Boulder Dam project. Davis Dam (completed later on the lower Colorado, downstream from Hoover Dam) was named in his honor.

Later Years and Legacy

After leaving the Reclamation Service, Davis served as chief engineer and general manager of the East Bay Municipal Utility District in the Oakland, California, area (roughly 1923–1930). He also worked as a consulting engineer on irrigation projects in the Soviet Union (Turkestan and Transcaucasia) in the early 1930s.

He died in Oakland on August 7, 1933, at age 72 and was buried in Rock Creek Cemetery in Washington, D.C., alongside his wife.

Davis combined technical expertise, bureaucratic skill, and a progressive-era faith in expert-led federal action and efficiency. While he did not live to see Hoover Dam completed, his early vision, surveys, advocacy for multipurpose development, and the Fall-Davis Report were instrumental in transforming the Colorado River from an uncontrolled, flood-prone waterway into a managed system of storage, power, and irrigation infrastructure that shaped the modern American Southwest.

White-nosed Coati (Nasua narica)

Posted on by

The white-nosed coati (Nasua narica), also known as the coatimundi, white-nosed coatimundi, pizote, antoon, gato solo, or tejón (depending on the region), is a medium-sized member of the raccoon family (Procyonidae). Native to wooded habitats ranging from the southwestern United States through Mexico and Central America to northwestern Colombia, it is distinguished by its long, flexible white-tipped snout, short rounded ears, and a long, slender, ringed tail that it often holds upright for balance. Adults typically weigh 4–6 kg (though males can reach up to 9 kg) and measure about 110 cm from nose to tail tip, with the tail making up roughly half that length. These agile, mostly diurnal omnivores forage on the ground and in trees for insects, fruits, small vertebrates, and other food, using their mobile snouts and strong claws.

A white-nosed Coati photographed on the Yucatan Peninsula. Photo by James L Rathbun
A white-nosed Coati photographed on the Yucatan Peninsula. Photo by James L Rathbun

Scientific Classification

KingdomAnimalia
PhylumChordata
ClassMammalia
OrderCarnivora
FamilyProcyonidae (raccoons and relatives)
GenusNasua
SpeciesNasua narica (Linnaeus, 1766)

Also known as coatimundi, pizote, antoon, or tejón in various Spanish-speaking regions. IUCN status: Least Concern.

Description (Physical Characteristics)

The white-nosed coati is a medium-sized, slender mammal related to raccoons. Head-body length typically ranges from 43–66 cm (17–26 in), with the long, slender, non-prehensile (or semi-prehensile) tail nearly as long (42–68 cm / 17–27 in), for a total length around 85–130 cm (about 3–4.3 ft). Weight is usually 3.5–6 kg (7.7–13 lb), though small females may weigh as little as ~3 kg and large males up to 7–9 kg (15–20 lb). Males are notably larger and about 30% heavier on average than females.

The coat is typically light buff to reddish, grayish, or dark brown, often with yellowish or silvery grizzling, especially on the sides of the arms; underparts are lighter. The distinctive facial markings include a white or pale band/patch around the tip of the long, flexible, slightly upturned snout (the “white nose”), white spots above and below each eye and on the cheeks, and a darker facial mask or band. The short, rounded ears have white interiors. The long tail is often ringed with darker bands (more distinct in juveniles) and is typically held upright while walking or foraging for balance and signaling. Feet have five toes with strong, curved claws suited for digging and climbing; front claws are longer.

The snout is highly mobile and sensitive, adapted for probing leaf litter and crevices. Sense of smell is particularly acute and primary for foraging.

Behavior

White-nosed coatis are primarily diurnal (active by day, especially mornings and late afternoons), unlike many other procyonids such as raccoons. They rest or sleep at night in trees, rocky ledges, or dens, though they may become more nocturnal in areas of high human disturbance or hunting pressure.

Social structure is distinctive: adult males are largely solitary (except during the brief mating season), while females and their offspring (including young males under ~2 years old) form cohesive social groups called bands. Bands typically number 4–20+ individuals (occasionally up to 30–40), often matrilineal with related females, though some unrelated individuals may join. Bands forage together, engage in mutual grooming (using teeth and claws), and use a variety of vocalizations, visual signals, and scent marking for communication. Young may be left with “babysitters” while others forage. Play-fighting occurs among juveniles and some females. Large bands may temporarily split into smaller foraging subgroups.

They are excellent climbers (using the tail for balance) but spend most of their active time on the ground. They are agile, strong, and opportunistic.

Reproduction: Mating occurs seasonally. Gestation lasts about 10–11 weeks (~70–77 days). Pregnant females leave the band to give birth in a tree nest (often palms or similar) to litters of 1–7 (commonly 2–6) altricial young. Mothers care for them in the nest for several weeks before rejoining the band with the mobile young. Young are weaned around 4 months and reach adult size by about 15 months. Sexual maturity is reached around 2 years for females (later effective breeding for males due to competition). Lifespan is typically up to ~7 years in the wild and averages ~14 years (occasionally longer, into the late teens or more) in captivity.

Habitat

White-nosed coatis are highly adaptable but prefer wooded habitats. They occupy tropical and subtropical dry and moist broadleaf forests, open woodlands, oak woodlands, pine-oak woodlands, riparian areas, canyons, and montane forests. They occur from sea level up to about 3,000 m (9,800 ft) elevation. They are less common in open grasslands, pure deserts, or heavily modified areas, though they may use agricultural edges or scrub. In the southwestern U.S., they favor oak woodlands and hardwood riparian canyons.

They forage both on the ground (leaf litter) and in the canopy (for fruit).

Range (Geographic Distribution)

The species ranges from the southwestern United States (southeastern Arizona, southern New Mexico; historically or marginally in parts of Texas, though status there is limited or uncertain) southward through most of Mexico (excluding the Baja Peninsula and parts of the central Sierra Madre), throughout Central America, and marginally into northwestern South America (far northwestern Colombia near the Panama border; some sources extend to western Colombia/Ecuador areas west of the Andes). Subspecies include N. n. molaris (northern populations including the U.S. and much of Mexico), N. n. narica (southern Mexico/Central America/Colombia), and others such as the smaller Cozumel Island form (N. n. nelsoni).

Food Sources (Diet)

White-nosed coatis are omnivorous and opportunistic foragers. The primary diet consists of invertebrates (insects and their larvae—beetles, grubs, ants, termites; spiders, scorpions, centipedes, and occasionally land crabs or worms), which they locate by sniffing through leaf litter with the snout held close to the ground and dig out with strong claws. Fruit is a major seasonal component (e.g., figs, hog plums, prickly pear and other cactus fruits, and many native tree fruits); bands may repeatedly visit productive trees and strip them. They also consume small vertebrates (lizards, snakes, frogs, rodents, occasionally birds or eggs), nuts, carrion, and occasionally anthropogenic food sources near human settlements. They may travel substantial distances daily (up to ~2 km) while foraging.

They play an ecological role as seed dispersers through fruit consumption and as mid-level consumers in food webs.

This report synthesizes information from reliable biological sources including IUCN assessments, museum/species accounts, and field studies. Populations are generally stable across much of the range but face localized pressures from habitat loss, hunting, and fragmentation in some areas.