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Rattlesnake Mountain (Benton County, Washington)

Rattlesnake Mountain (Native American name Lalíik meaning "land above the water") is a 3,531 ft (1,060 m) windswept treeless sub-alpine ridge overlooking the Hanford nuclear site. Parts of the western slope are privately owned ranchland, while the eastern slope is under the federal protection of the Arid Lands Ecology Reserve, a unit of the Hanford Reach National Monument, managed by the United States Fish and Wildlife Service. The mountain is the second highest point in Benton County, with its neighbor Lookout Summit surpassing it by only 98 ft (30 m).

Rattlesnake Mountain
The view of Rattlesnake Mountain from the Horn Rapids Golf Course in Richland.
Highest point
Elevation3,531 ft (1,076 m) [2][3]
Prominence840 ft (260 m) [2]
Isolation1.55 mi (2.49 km) [2]
Parent peakLookout Summit
ListingBenton County highest peaks 2nd
Coordinates46°24′56″N 119°37′49″W / 46.41556°N 119.63028°W / 46.41556; -119.63028Coordinates: 46°24′56″N 119°37′49″W / 46.41556°N 119.63028°W / 46.41556; -119.63028[1]
Rattlesnake Mountain is located in Washington (state)
Rattlesnake Mountain
Rattlesnake Mountain
Parent rangeRattlesnake Hills
Topo map
  • USGS Iowa Flats
  • USGS Snively Basin

Rattlesnake Mountain is notable for its high wind speeds, with the highest recorded being around 150 mph (241 kilometers per hour).[4]


The Yakama Nation referred to Rattlesnake Mountain as Lalíik, meaning "land above the water". Some historians speculate that the origin of the name Lalíik refers to the inundation of the Columbia River Plateau during the Missoula Floods, as Rattlesnake would have been one of the few mountains not completely inundated by flood waters reaching depths of 1200 ft (366 m). Geologists have found glacial erratics on Rattlesnake at heights up to this level.[5] However, there is scant evidence placing human settlements in the area at the time of the floods, 12 to 13 thousand years ago. Lalíik is held sacred by native peoples of the Columbia Plateau, including the Nez Perce, Umatilla, Wanapum, Cayuse, Walla Walla, and Yakama, and remains a spiritual epicenter to this day.[6]

In 1943, Rattlesnake Mountain was seized by the United States government under eminent domain and became a buffer zone for the nuclear project at the Hanford site. In 1955, US Army installed a Nike Ajax missile base on the southeastern end of the ridge and maintained it until December 1958, when it was closed.[7]

Rattlesnake Mountain ObservatoryEdit

The Rattlesnake Mountain Observatory was established at the summit in 1966, utilizing some of the former missile base infrastructure, and remained there until its relocation near Wallula, WA in 2009. The observatory's main telescope was installed in 1971 and is a 32-inch (0.8-meter) telescope housed inside a 24-foot domed enclosure. This telescope is the largest permanently mounted telescope in Washington State. The telescope was used regularly through the early 1980s, but soon fell into disuse. Due to its location, renovations and upgrades were done to allow for remote control. Observatory operations are directed by a local nonprofit group founded by scientists and engineers from the Pacific Northwest National Laboratory at Hanford.[8]

It was announced 14 March 2008 that the Department of Energy would not renew the permit, license or easements for the observatory or most of the other entities that maintain communication equipment on the mountain. DOE instead intends to return the area to its natural conditions, citing the cultural sensitivity of the area.[9] The removal of the observatory from Rattlesnake Mountain began in the latter part of May, 2009. Most of the work, including the removal of the telescope itself, was completed in June of the same year. In late 2012, the telescope moved into its new home at Pacific Northwest Regional Observatory in the hills near Wallula, Washington.[10]

Public accessEdit

Section 3081, "Ensuring public access to the summit of Rattlesnake Mountain in the Hanford Reach National Monument",[11] of the Carl Levin and Howard P. “Buck” McKeon National Defense Authorization Act for Fiscal Year 2015 (H.R. 3979 (113th))[12] directs the Secretary of the Interior to provide public access (including motorized access) to the summit of Rattlesnake Mountain in the Hanford Reach National Monument in the state of Washington. This law was enacted — Signed by the President on Dec 19, 2014. The provision is supposed to help with tourism and scientific undertakings.[13] The Native American community has objected to this action.[14] Public access is expected to begin in Fall of 2019.[15]


Rattlesnake Mountain is often falsely claimed to be the tallest treeless mountain in the world. However, it is the tallest treeless mountain in North America. [16]


  1. ^ "Maiden Springs Quadrangle". United States Geological Survey. Retrieved March 14, 2018.
  2. ^ a b c "Rattlesnake Mountain, Washington". Retrieved May 5, 2018.
  3. ^ "Rattlesnake Mountain". Geographic Names Information System. United States Geological Survey. Retrieved 2018-03-14.
  4. ^ "Hanford Site Virtual Tours". Department of Energy. Archived from the original on 2008-09-17. Retrieved 2007-10-13.
  5. ^ Bjornstad, Bruce; Karl Fecht (2002-10-19). "Ice-Age Floods Features in the Vicinity of the Pasco Basin and the Hanford Reach National Monument" (.pdf). Retrieved 2007-11-07.
  6. ^ Prengaman, Kate (2014-12-14), "Yakamas unhappy defense bill to open sacred summit to public", The Seattle Times
  7. ^ "Nike Missile Bases: Washington State Cold War Defenses". HistoryLink. Retrieved 2019-02-08.
  8. ^ "Automation of Rattlesnake Mountain Observatory—Science Education and Opportunity for the 21st Century". Retrieved 2007-10-12.
  9. ^ Cary, Annette (2008-03-22). "DOE to evict Rattlesnake Mountain tenants". Tri-City Herald.
  10. ^ "Rattlesnake Mountain telescope gets new home". Retrieved 2013-01-06.
  11. ^
  12. ^ "Carl Levin and Howard P. "Buck" McKeon National Defense Authorization Act for Fiscal Year 2015 (2014 - H.R. 3979)".
  13. ^ Kasperowicz, Pete (11 June 2013). "To the top of Rattlesnake Mountain". The Hill. Retrieved 13 June 2013.
  14. ^ "Congress Approves Bill to Force Opening Access to Yakama Nation Sacred Site - Last Real Indians".
  15. ^ McIntosh, Brittany (October 15, 2018). "After 70 years public access to Rattlesnake Mountain summit will re-open next fall". KNDU-TV. Retrieved October 15, 2018.
  16. ^ Davis, Jean Carol; Vickie Sillman Bergum. Benton County Place Names. East Benton County Historical Society. OCLC 37857532.

External linksEdit