Upper Mesa Falls is a waterfall on the Henrys Fork in the Caribou-Targhee National Forest. Upstream from Lower Mesa Falls, it is roughly 16 miles (26 km) away from Ashton, Idaho.[2]

Upper Mesa Falls
Upper Mesa Falls in June, 2008
Map
LocationFremont County, Idaho
Coordinates44°11′16″N 111°19′48″W / 44.18778°N 111.33000°W / 44.18778; -111.33000
TypeBlock
Elevation5,600 feet (1,707 m)
Total height114 feet (35 m)[1]
WatercourseHenrys Fork (Snake River)

Upper Mesa Falls is roughly 114 feet (35 m) high and 200 feet (61 m) wide.[3]

Formation

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Mesa Falls Tuff, which is the rock over which Upper Mesa Falls cascades, was formed 1.3 million years ago. A cycle of rhyolitic volcanism from the Henrys Fork caldera deposited a thick layer of rock and ash across the area.[4] This layer compressed and hardened over time.

Between 200,000 and 600,000 years ago, the river eroded a wide canyon which was subsequently partly filled with basalt lava flows. The Henrys Fork of the Snake River then carved the channel through the basalt; which is the inner canyon seen today.

See also

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Video of the Upper Mesa Falls

References

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  1. ^ "Upper Mesa Falls, Idaho". Public Lands Information Center. 2008. Retrieved 2008-08-13.
  2. ^ "Upper Mesa Falls". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. Retrieved January 15, 2015.
  3. ^ "Mesa Falls Near Ashton Idaho".
  4. ^ Shallat, Todd A; Bentley, E B (1994). Snake: the plain and its people. Boise, ID: Boise State University. p. 53. ISBN 978-0-932129-12-3. OCLC 31689273.
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