Upper Mesa Falls
{{Infobox waterfall
| name = Upper Mesa Falls
| photo = Mesa_Falls_4.JPG
| photo_width = 200
| photo_caption = Upper Mesa Falls in June 2008
| location = Fremont County, Idaho
| coords = {{coord|44|11|16|N|111|19|48|W}}
| elevation = {{convert|5600|ft|m|0}}
| type = Block
| height = {{convert|114|ft|m|0}}{{cite web
| title = Upper Mesa Falls, Idaho
| publisher = Public Lands Information Center
| year = 2008
| url = http://www.publiclands.org/explore/site.php?search=YES&back=Search%20Results&id=7121
| access-date = 2008-08-13}}
| width =
| height_longest =
| average_width =
| number_drops =
| average_flow =
| watercourse = Henrys Fork (Snake River)
| world_rank =
}}
Upper Mesa Falls is a waterfall on the Henrys Fork in the Caribou-Targhee National Forest. Upstream from Lower Mesa Falls, it is roughly {{convert|16|mi|km}} away from Ashton, Idaho.{{cite gnis|392638|Upper Mesa Falls|January 15, 2015}}
Upper Mesa Falls is roughly {{convert|114|ft|m}} high and {{convert|200|ft|m}} wide.{{cite web |url=http://www.westyellowstonenet.com/attractions/mesa_falls.php |title=Mesa Falls Near Ashton Idaho}}
Formation
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.{{cite book
| last = Shallat
| first = Todd A
|author2=Bentley, E B
| title = Snake: the plain and its people
| publisher = Boise State University
| year = 1994
| location = Boise, ID
| pages = 53
| oclc = 31689273
| isbn = 978-0-932129-12-3}}
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
References
{{reflist}}
External links
{{commons category|Upper Mesa Falls}}
- [http://www.fs.usda.gov/recarea/ctnf/recreation/outdoorlearning/recarea/?recid=80612&actid=120 Mesa Falls Visitor Center] (USDA Forest Service - Caribou-Targhee National Forest)
{{Idaho}}
{{Authority control}}
Category:Landforms of Fremont County, Idaho
Category:Tourist attractions in Fremont County, Idaho
Category:Articles containing video clips
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