Lemhi Pass
Lemhi Pass | |
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![]() View from Lemhi Pass | |
Elevation | 7,373 ft (2,247 m) |
Traversed by | Unpaved road |
Location | Lemhi County, Idaho/Beaverhead County, Montana,![]() |
Range | Bitterroot Rangeof theRocky Mountains |
Coordinates | 44°58′27″N113°26′42″W/ 44.97417°N 113.44500°W |
Lemhi Pass | |
Nearest city | Tendoy, Idaho |
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Coordinates | 44°58′27″N113°26′42″W/ 44.97417°N 113.44500°W |
NRHP referenceNo. | 66000313 |
Significant dates | |
Added to NRHP | October 15, 1966[1] |
Designated NHL | October 9, 1960[2] |
Lemhi Passis a highmountain passin theBeaverhead Mountains,part of theBitterroot Rangein theRocky Mountainsand withinSalmon-Challis National Forest.The pass lies on theMontana-Idahoborder on theContinental Divide,at anelevationof 7,373 feet (2,247 m)above sea level.It is accessed via Lemhi Pass Road in Montana, and the Lewis and Clark Highway in Idaho, both gravel roads. Warm Springs Road, which roughly follows the divide in Montana, passes just west of the pass's high point.
History
[edit]The pass gained importance in the 18th century, when theLemhi Shoshoneacquired horses and used the route to travel between the two main parts of their homeland.[3]From the time of theLouisiana Purchasein 1803 until theOregon Treatyin 1846 the pass marked the western border of the United States. On August 12, 1805Meriwether Lewisand three other members of theLewis and Clark Expeditioncrossed the Continental Divide at Lemhi Pass. Lewis found a "large and plain Indian road" over the pass.[4]This was the first time that white men had seen present-day Idaho:
We proceeded to the top of the dividing ridge from which I discovered immense ranges of high mountains still to the West of us with their tops partially covered in snow
The next day Lewis metCameahwaitand his band of Shoshone, and returned with them across the pass to meet Clark. On August 26, 1805 the entire expedition crossed the pass.[5]
In the early 19th century the pass was regularly used by theBlackfootpeople, so that in 1824Alexander Rossreferred to the route as the Blackfoot route.[3]At that time the pass itself was known as North Pass, to distinguish it fromSouth Pass.[3]The pass derives its present name fromFort Lemhi,founded in 1855 byMormonmissionaries who were the first non-Indians to establish a sustained relationship with theSalmon RiverIndian people.
During the mining era the pass was used by stagecoaches, but the route fell into disuse after 1910, when theGilmore and Pittsburgh Railroadwas built through the nearbyBannock Pass.[3]Only a single track dirt road now crosses the pass.
The pass was designated aNational Historic Landmarkin 1960.[2]
Mineral resources
[edit]The Lemhi Pass district has been found to host manylanthanideminerals and the richest deposit ofthoriumin the US. In a study of 31 samples taken from 21 different veins, the ratio ofrare-earth elements(REEs) in the area is estimated to be between 0.05-9.2%. This depends largely on the localized mineralogy and REE mineralization. Most commonly the thorium is found asthoritehosted inquartzveins, whereas REEs are contained withinmonazite.[6]
The deposits lie within quartz veins hosted inPrecambrianrock with minerals such ashematite,apatite,feldspar,thorite and monazite present. The monazite is found to be enriched in the middle rare earths, specificallyneodymium(Nd), as there is estimated to be 35 weight percent of Nd in the monazite.[7]Neodymium,cerium,gadolinium,yttrium,anddysprosiumare the top lanthanide minerals recorded to be attainable in the Lemhi Pass.[6]
See also
[edit]- Mountain passes in Montana
- List of National Historic Landmarks in Idaho
- List of National Historic Landmarks in Montana
- National Register of Historic Places listings in Lemhi County, Idaho
- National Register of Historic Places listings in Beaverhead County, Montana
References
[edit]- ^"National Register Information System".National Register of Historic Places.National Park Service.April 15, 2008.
- ^ab"Lemhi Pass".National Historic Landmark summary listing.National Park Service. Archived fromthe originalon January 10, 2008.RetrievedJune 11,2008.
- ^abcdIdaho State Historical Society Reference Series No. 280Archived2010-07-07 at theWayback Machine
- ^Ambrose, S.E. (1996)Undaunted CourageISBN0-684-82697-6p.266
- ^Ambrose, pp.269-282
- ^abOccurrence and Distribution of Rare Earths in the Lemhi Pass Thorium Veins, Idaho and MontanaMortimer H. Staatz, Van E. Shaw, and James S. Wahlberg (1972)
- ^"Rare Earth Elements and Other Critical Metals in Idaho, Geo Note, Idaho Geological Survey, Virginia S. Gillerman, January 2011
External links
[edit]![](https://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
- National Park Service- Lemhi Pass
- Reading 2: Lemhi Pass and Lolo TrailfromThe Lewis & Clark Expedition: Documenting the Uncharted Northwest Name,a National Park Service Teaching with Historic Places (TwHP) lesson plan.
- National Register of Historic Places Registration: Lemhi Pass
- Accompanying 10 photos, from 1958 and 1962
- Mountain passes of Idaho
- Mountain passes of Montana
- National Historic Landmarks in Idaho
- National Historic Landmarks in Montana
- Great Divide of North America
- Landforms of Lemhi County, Idaho
- Landforms of Beaverhead County, Montana
- Borders of Idaho
- Borders of Montana
- Transportation in Lemhi County, Idaho
- Transportation in Beaverhead County, Montana
- Beaverhead-Deerlodge National Forest
- Salmon-Challis National Forest
- Natural features on the National Register of Historic Places in Montana
- National Register of Historic Places in Lemhi County, Idaho
- National Register of Historic Places in Beaverhead County, Montana
- Lewis and Clark Expedition