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Mt. Jefferson



1.6 mile 2.6 kilometer point to point
62% Runnable


Ascent: 1,239' 378 m
Descent: -123' -37 m
High: 10,118' 3,084 m
Low: 8,997' 2,742 m


Avg Grade: 16% (9°)
Max Grade: 43% (23°)


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Trail shared by Jeff Fullmer


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A beautiful singletrack trail that takes you to the top of Mt. Jefferson in Island Park.

Jeff Fullmer

Features Views · Wildflowers · Wildlife

After turning off of the highway, the road is closed during the winter with a gate a few miles in.

Need to Know

Island Park has a high density of grizzly bears. Bear spray is always recommended for this area, especially if running alone.

Runner Notes

All but 2 or 3 sections are runnable on the way up if you are in fairly good shape. You can run the entire way back.


Turning onto Sawtell Peak Road off the main highway, travel for 9 miles and go almost to the top of Sawtell Peak. There is a pullout parking lot at the trailhead to the south (left) of the dirt road. The trailhead is on the west side of where the Forest Service signage is at.

A majority of this trail skirts along the Idaho/Montana border. It offers fantastic views into both states. Follow the Sawtell Peak #165 trail to start; this trail is well-marked until you need to split off after 2.3 miles. It will pop you up to sidehills and ridgelines the rest of the way.

The trail is poorly marked where you turn. Pretty much non-existent and you'll only know when to turn by following the GPX track or Forest Service map. You'll find the trail in spots, along with multiple Idaho/Wyoming land survey markers. There are some challenging sections but nothing terribly serious. You can follow the Sawtell Peak #165 trail down to Lake Marie and then work your way up the non-existent trail to the northwest ridge for added milage, or go back down that way.

Flora & Fauna

A wide variety of plants/trees and critters in the area. This is an ideal early to mid-summer run. Lots of wildflowers.

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in Idaho


5 Views Last Month
28 Since Sep 3, 2019



Looking back to the northeast and the Sawtell Peak ridgeline.
Sep 3, 2019 near West Ye…, MT
On the ridge looking out over Henry's Lake to the north.
Sep 3, 2019 near Island…, ID
On top of Mt. Jefferson.
Sep 3, 2019 near West Ye…, MT
The turn. It is not marked, but you take it shortly after you start hiking to the north and are done with the downhill section.
Sep 3, 2019 near Island…, ID
There are several state markers along this route.
Sep 4, 2019 near Island…, ID


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