Day 16: Big Springs to Grassy Lake Reservoir (70.8 miles, 2,796ft)
We started the day backtracking about a mile from the campground to the Yellowstone Branch Line Trail, a rail-to-trail that runs from near West Yellowstone down to Warm River. The surface quality was, to say the least, soft and quite rutted in sections—a bit slow, but flat.
Around 10 miles into the day, we hopped over onto a dirt road that ran parallel to the rail-to-trail for a few quicker miles. We returned to the rail-to-trail as it approached Warm River and were rewarded with some wonderful views as we rode above the river.
Further down the trail, we arrived at the Warm River Campground—a lovely little campground with water, pavilion, and quite a few campsites.
We climbed slowly on paved roads to the Targhee National Forest, where we continued on a rough dirt road, ascending gradually through forest and wetland. Along the way, we passed from Idaho into Wyoming.
After a steeper climb we arrived at the Grassy Lake Reservoir.
From the dam, we climbed steeply away from the reservoir, before descending to the east side, where we stopped at a primitive campsite along the lakeshore. (There was a bear box but no pit toilet or picnic table.) A few minutes later we Anna and the kids arrived, navigating to a predetermined point using Gaia GPS, and we settled in for the night.