Ubehebe Crater (pronounced “you-bee-HEE-bee”) is one of the most striking and geologically dramatic features in Death Valley National Park, California. Located in the northern part of the park at the base of the Cottonwood Mountains (near the Racetrack Playa area), it is the largest and most prominent of a cluster of volcanic explosion craters known as the Ubehebe Craters or Ubehebe volcanic field. This maar-type crater stands out amid the park’s predominantly sedimentary and tectonic landscape as evidence of relatively recent volcanic activity in an otherwise arid, non-volcanic region.
Geological Description
Ubehebe Crater is a classic maar—a broad, shallow volcanic crater formed primarily by explosive phreatomagmatic eruptions (interactions between rising magma and groundwater). It measures approximately half a mile (about 0.8–1 km) in diameter and reaches depths of 500–777 feet (152–237 m), with steep, unstable inner walls composed of layered ejecta.
- Formation Mechanism: The crater resulted from basaltic magma rising toward the surface and encountering groundwater in porous sedimentary rocks (primarily Miocene fanglomerates and sandstones). The intense heat caused the water to flash-boil into superheated steam, building enormous pressure. This triggered violent steam-driven explosions that fragmented and ejected large volumes of country rock (pre-existing sedimentary material) along with juvenile basaltic material. The blasts pulverized rock into ash, lapilli, bombs, and blocks, hurling them outward in pyroclastic surges and fallout deposits. Unlike typical lava-flow volcanoes, maar eruptions produce little to no sustained lava flows; instead, they create wide, low-angle rims of mixed ejecta.
- Composition and Deposits: The ejecta blanket covers roughly 40 km² (15 mi²) around the craters. Deposits consist of approximately one-third basaltic scoria, bombs, and spatter (dark, fresh-looking volcanic material) and two-thirds comminuted fragments of older sedimentary rock (light-colored sandstone, conglomerate clasts). Layers alternate in color—dark basaltic ash and lighter sedimentary breccia—creating vivid banding visible on the crater walls and rim. Pyroclastic surge deposits (dense, ground-hugging flows of hot gas and debris) extend unusually far (up to 9–15 km in some directions, based on recent studies), preserved better here due to the arid environment with minimal erosion.
- The Cluster: Ubehebe is the northernmost and youngest crater in a group of about 7–12 overlapping maars aligned roughly north-south over 1.5 km, with additional smaller vents east-west and isolated features. Smaller nearby craters include Little Hebe Crater (a nested or satellite maar) and others with tuff rings.
- Age: Estimates vary due to challenges in dating young maars, but most recent research places the main eruptive sequence (including Ubehebe Crater) at approximately 2,100 years ago (around 100 BCE), based on radiocarbon dating, paleomagnetism, and stratigraphic studies. Earlier estimates ranged from 800–7,000 years old, with some suggesting the entire cluster formed in a brief period (weeks to months) from a single magmatic pulse rather than over centuries.
The eruptions exposed colorful underlying sedimentary layers, revealing Death Valley’s deeper geologic history of ancient lake beds, alluvial fans, and tectonic basin fill.
History of Discovery, Naming, and Study
- Indigenous Context: The area lies within traditional territories of the Timbisha Shoshone people. “Ubehebe” derives from a Shoshone term possibly meaning “big basket” or “big hole in the ground,” reflecting the crater’s appearance. Indigenous knowledge of the landscape predates European-American exploration.
- Euro-American Discovery: Prospectors and explorers encountered the crater in the late 19th/early 20th century amid Death Valley’s mining booms. It was noted for its dramatic appearance but not initially recognized as volcanic due to the region’s focus on gold, silver, and borax.
- Scientific Recognition: Early 20th-century geologists identified its volcanic origin. Detailed studies intensified in the late 20th and early 21st centuries. Key research includes:
- Stratigraphic and paleomagnetic work showing a short eruptive duration.
- 2016 studies on the cluster’s sequence (phreatomagmatic followed by minor magmatic phases).
- 2022 research (led by Greg Valentine, University at Buffalo) revealing wider pyroclastic surge runout than typical for maars, implying underestimated hazard zones around similar volcanoes worldwide. Deposits preserved far from the vent highlight risks in arid settings.
- Modern Status: Ubehebe Crater is a popular, accessible viewpoint in Death Valley National Park. A paved road leads to a parking area and overlook at the rim, with a short trail along the rim offering panoramic views. The interior is extremely hazardous (loose, steep slopes prone to rockfall), and descent is prohibited without permits (rarely granted). It serves as an educational site illustrating explosive volcanism, groundwater-magma interaction, and recent geologic activity in a tectonically active region.
Ubehebe Crater stands as a youthful reminder that Death Valley’s geologic story is ongoing—its formation just a few millennia ago underscores the potential for future volcanic events in this dynamic landscape, even if probabilities remain very low. Visitors experience one of the park’s most otherworldly sights: a stark black-rimmed pit contrasting with multicolored badlands under vast desert skies.
Hiking
The road into Ubehebe serves as the starting points to the Race Track Valley Road, Teakettle Junction and Hunter Mountain Road.
There are a few separate hiking opportunities while exploring the crater.
The crater rim trail, which is about 1.5 miles long, circumnavigates the crater and allows access to Little Hebe crater. The trail has some slight elevation gain, however could be more difficult to hikes with balance issue due to the unstable soil.
There is also a trail down the the bottom of the crater. This is a short trail and very easy going down. The difficulty is hiking back up the 600 feet elevation lost on the way down, in loose volcanic soil.