The high elevation and thick timber make this trail one of the last in the region to shed snow, and drifts are common into late June. The trail to Cottonwood Lake is very popular with backcountry horsemen and horsewomen, so be alert, and make sure to park courteously, leaving room for horse trailers to turn around.
The trail to Cottonwood Lake is a moderate climb. From the lake, the trail climbs steeply to the top of Thunderbolt Mountain via the L.O. Connection. The junction is at the north end of the lake; if you carry on farther than that you have missed it and are headed into the Little Blackfoot watershed.
Take the Bernice exit of I-90 (Exit 151) and follow the Boulder River Road (staying to the left). Stay on the Boulder River road to the Thunderbolt Creek road, which is directly opposite the Whitehouse Campground. The junction is a distinctive Y and is signed. The Thunderbolt Creek road ends at the trailhead.
Local Trail Association
More Stats for Thunderbolt Mountain Trail 65 mountain bike trail
Altitude change1,243 ft
Altitude min6,393 ft
Altitude max7,636 ft
Altitude start6,393 ft
Altitude end7,636 ft
Distance climb4 miles
Distance down5,057 ft
Distance flat1,179 ft
- view trail stats
- Snow Packed
- Snow Covered
- Freeze/thaw Cycle
- Prevalent Mud
- Very Dry
Thunderbolt... Trail Reports
Nov 1, 2017 @ 11:24amNov 1, 2017
|reporter First real snowfall of 2017/18|
Sep 18, 2017 @ 1:00pmSep 18, 2017
Sep 16, 2017 @ 11:37amSep 16, 2017
Aug 16, 2015 @ 11:17amAug 16, 2015
May 31, 2015 @ 6:57amMay 31, 2015
|As of Memorial Day weekend, there were significant drifts in the last half-mile below Cottonwood Lake, and solid snow above the lake.|
Routes with this trail
|Thunderbolt Mountain||13 miles|
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