The hike to Hollowtop Lake, Deep Lake, and Skytop Lake located in the Tobacco Root Mountains is a gorgeous full-day hike or overnighter. The trail starts from a well marked trailhead. You follow a rutted trail next to North Willow Creek for several miles. After about 2 miles you will cross the creek. The next ~1.25 miles take you over large open sage fields before going into denser forests for the remainder of the hike. You’ll arrive at Hollowtop Lake after another mile or so. This lake has great views of Hollowtop mountain and Mt Jefferson. You’ll also notice some blowdown on the far end of the lake. Unfortunately the trail to Deep Lake used to pass through this. As of writing this, the blowdown was a complete mess and the trail is not easily found. We ended up using our GPS to find an alternate route to the trailless Skytop Lake first and then came back down to Deep Lake on the way out. Hopefully an alternate route will be built soon as the upper two lakes are quite breathtaking!