Logan State Park is a 17-acre Montana state park on the north shore of Middle Thompson Lake in Lincoln County, run by Montana Fish, Wildlife & Parks. It sits in the middle of the much larger Thompson Chain of Lakes State Park, a 3,000-acre strip of public shoreline that follows US Highway 2 for about 20 miles past Upper, Middle and Lower Thompson lakes, McGregor Lake and a string of smaller ponds. Logan is the developed hub of that chain, with a grassy swimming beach, a paved boat ramp and dock, rental boat slips and a 37-site campground under western larch, Douglas-fir and ponderosa pine.

The entrance is right on US 2 at 77518 US Hwy 2, roughly 45 miles southeast of Libby and about 45 miles west of Kalispell, so there is no back-road driving to reach it. Pull in past the entrance kiosk and follow the park road down toward the boat ramp and day-use parking near the water. The beach is a short walk from the lot. The highway runs just above the park, and you will hear truck traffic from the shore.

Swimming is listed by FWP as an official activity here. The swim area is small and sits next to the boat ramp and dock, with a grassy bank and picnic tables close by. West of the ramp the shoreline turns to marsh, so plan on staying near the beach. Middle Thompson is a clear, cold mountain lake at about 3,300 feet and it stays chilly into early summer. There are no lifeguards. Boats launch a few yards away, and the lake is popular for water skiing and fishing, so keep swimmers inside the beach area and watch for boats backing trailers in and out of the ramp.

Montana residents who pay the $9 state parks fee with their annual vehicle registration get in free. Everyone else pays the day-use entrance fee: $8 per vehicle, or $4 for walk-ins, cyclists and bus passengers. Nonresidents holding the $50 annual Nonresident Entrance Pass or the $35 seven-day pass get in free. The park is open all year from 7 a.m. to 10 p.m. Water, showers and the A loop close in late September and reopen in May, and the boat slips come out in mid-September and go back in each May. Camping is $4 to $34 per night depending on the site and season, and sites can be reserved through ReserveAmerica.

This is bear country. FWP requires all food and other attractants to be stored in a vehicle or a hard-sided container when not in use, day or night, and garbage goes in the bear-resistant dumpsters. Boats, paddleboards and float toys coming from other waters must be cleaned, drained and dried first to keep aquatic invasive species out of the chain. Check FWP's restrictions and closures page before a trip, since fire, drought or maintenance work can close parts of the park.

Beyond the beach there are flush toilets, showers, drinking water in season, a playground, a horseshoe pit, a picnic shelter and a short nature trail. Anglers come for trout, kokanee, largemouth bass, yellow perch and northern pike. If you want quieter water, the rest of Thompson Chain of Lakes State Park has primitive campsites and boat ramps on Upper and Lower Thompson, McGregor, Horseshoe and Loon lakes, though those roads are rough and not suited to large trailers.