Such a beautiful payoff when you get to the lake, but OMG talk about uphill!!! This hike is quite the climb. Go in the summer. You will be covered in sweat by the time you get there and won't even mind that the lake is freezing cold! Much more challenging trail than the nearby Revett Lake, even though the lakes are almost identical.
Followed the GPS route listed here. No falls, I think this trail is being confused with one down in the Bittterroot Valley with the same name. This trail leads you up a ridge for a ways with views of Lolo Peak. Some cool open views once you get to the top of the ridge.
Fairly easy out and back on a well worn trail until the scramble to the peak. People get lost coming off the peak in fog or snow so have a compass or know where your are when conditions are poor. Great views of the bitter roots, missions, Rattlesnake, missoula and mission valleys, and glacier and the cabinets to the north and northwest.
The hike to Blossom Lake is well worth the effort. This is certainly on my top 20 list of day hikes. The drive to the trail head is quite scenic. There is amply parking at the trail head to Blossom Lake. (Please note, it is the same parking for the trail head to Revett Lake) The trail to Blossom Lake is well defined and easy to follow. There are some fair inclines along the way, but I met an elderly lady on her way down, who had just finished the hike with two artificial knees. It is not a Sunday stroll in the park, but it is not an arduous trek either.
UPPER BLOSSOM LAKE
If you have already taken the effort to drive up to Thompson Pass, and hiked to Blossom Lake, muster up a bit more energy, and go further, to Upper Blossom Lake. It is smaller than Blossom Lake, but in my opinion, it is the lovelier of the two.
Alright, you have already committed yourself to Blossom Lake and Upper Blossom Lake. Are you SURE you aren't going to press on just a bit further to Pear Lake? On this fine day in November, I did just that, and found it a picture of stunning beauty, frozen over like some winter wonderland. Bring an extra snack and another bottle of water, and do all three lakes. It is well worth it!