God bless Lookout Ski Area. They’re a winter gem located halfway between Missoula and Spokane on I-90, right on the Idaho border. They’re almost always the first place to flip the switch on their chairlifts each year and they work hard to continually add new terrain. PLUS, they still offer a one-ride chairlift ticket, which you can use to reach some great backcountry skiing around the St. Regis Lakes.
Buy two tickets for each person in your party, one for your way out and one for use on your way back in. For just a few bucks on tickets, you can snag the first thousand vertical feet on a chair and jumpstart your day. At the top of Chair 1 you’ll find yourself atop 5,650-foot Runt Mountain. Veer right as you get off the lift and head down Rainbow Ridge. This run follows the state line, and about a third of the way down you’ll veer off to your right and into the trees onto an established service road.
This off-piste path begins to switch back several times and you want to watch for other tracks while paying attention to the geography and fall line. You’ll lose a little elevation here but then catch the next ridge where you’ll switch into uphill mode. Continue west following the state line. After about two miles you will have passed several slopes on your left that lead down to the drainage below. Any of these are decent options, but there’s a bit of an east-facing aspect closer to the two-mile mark. Many of the other slopes you passed have southern exposure and can get a bit banged up if you aren’t on the heels of a storm. Additionally, this eastern aspect seems to harbor a few more open slopes than the others. Pick your way down and make sure you’ve checked in on the local avalanche forecast to help make your own slope assessments.
At the bottom, you’ve got the option of route-finding your way back up for another lap, or starting your trek back to the area, depending on how much time you’ve got. If you’re lucky, you could run across a snowmobiler that will offer to drag you back on the trail back to Lookout Ski Area. Either way, you’ll end up passing along the “Montana Side” of the area and (assuming you did buy two tickets) you can hop on the backside chair and ride back up to the top of Runt Mountain. This way you’ll even sneak in one more run back down to the lodge and parking lot below.For a fully self-propelled outing in either summer or winter, you can reach the lakes from the access road just east of Lookout Pass on the Montana side. From there, it's a three-mile trip into the basin on an abandoned road.