Near Tendoy in Lemhi County, Idaho — The American West (Mountains)

"Immence Ranges of High Mountains Still to the West of Us…"

- Meriwether Lewis, August 12, 1805

Photographed by Barry Swackhamer, June 24, 2017

1. "Immence Ranges of High Mountains Still to the West of Us..." Marker

Caption: (legend) The Lewis and Clark Trail: RED - 1805 westward route; BLUE - 1806 eastward route; YELLOW - highlights the portage across the Rocky Mountains.

Inscription. Filling in the Blanks The maps of North America carried by Lewis and Clark showed only a vast, uncharted space between the Mandan villages of the Missouri Rier and the Pacific Coast. The mountains separating the Missouri and Columbia river drainages were drawn as a single ridge. There was hope of finding a simple land route, or portage, over the Rocky Mountains. Map makers two hundred years ago did not know what the West was like.

The modern map above is just a small slice of the United States along the Lewis and Clark Trail. Imagine trying to find you way across this land without such a map. Lewis and Clark, and many others who follow after them, have filled in the blanks for us.

Erected by Beaverhead-Deerlodge & Salmon-Chaillis National Forest.

Topics and series. This historical marker is listed in these topic lists: Exploration • Natural Features. In addition, it is included in the Lewis & Clark Expedition series list. A significant historical date for this entry is August 12, 1805.

Location. 44° 58.876′ N, 113° 26.771′ W. Marker is near Tendoy, Idaho, in Lemhi County. It can be reached from the intersection of

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Forest Road 158 and Warm Springs Road (Forest Road 185) when traveling south. Touch for map. Marker is in this post office area: Tendoy ID 83468, United States of America. Touch for directions.

Regionally, this marker is in Central Idaho — Sawtooth Range.

It is also in the American Mountain West

and in the Lewis & Clark Corridor.

Globally, it is in North America,

the Rocky Mountains,

the Western Hemisphere,

the Western World,

and the Anglosphere.

Other nearby markers. At least 8 other markers are within walking distance of this marker: A Communication Across the Continent by Water (a few steps from this marker); Agency Creek (approx. 0.2 miles away); Lemhi Pass (approx. 0.2 miles away); From Route ... To Road (approx. 0.4 miles away); Crossing the Great Divide (approx. 0.4 miles away); "Most Distant Fountain" of the Mighty Missouri (approx. ¾ mile away in Montana); The Beginning of the "Endless Missouri" (approx. ¾ mile away in Montana); Sacajawea Memorial Area (approx. ¾ mile away). Touch for a list and map of all markers in Tendoy.

More about this marker. This marker is located on the Continental Divide Trail.
This

"Immence Ranges of High Mountains Still to the West of Us..." Marker, detail image. Click for full size.

Photographed by Barry Swackhamer, June 24, 2017

2. "Immence Ranges of High Mountains Still to the West of Us..." Marker, detail

Caption: (legend) The Lewis and Clark Trail: RED - 1805 westward route; BLUE - 1806 eastward route; YELLOW - highlights the portage across the Rocky Mountains.

marker is on the Lewis and Clark National Back Country Byway and Adventure Road. The Byway is a 36 mile loop from Tendoy, Idaho to Lemhi Pass and back to Tendoy over gravel roads with a 4000 foot gain and loss in elevation. There are 10 designated stops with pullouts on the Byway and over two dozen information panels and markers on route. Estimated travel time is about 3 hours.

Additional commentary.
1. Spelling of Immance on the marker
The spelling of Immence is taken verbatim from the marker, presumably verbatim from Meriwether Lewis' account of the trip.

— Submitted June 30, 2020, by Devry Becker Jones of Washington, District of Columbia.

Photographed by Barry Swackhamer, June 24, 2017

3. "Immence Ranges of High Mountains Still to the West of Us..." Marker

This marker is on the right, toward the background. DIRTY CAMERA LENS :(

Credits. This page was last revised on February 22, 2026. It was originally submitted on November 2, 2017, by Barry Swackhamer of Brentwood, California. This page has been viewed 542 times since then and 17 times this year. Photos: 1, 2, 3. submitted on November 2, 2017, by Barry Swackhamer of Brentwood, California.