Colored stones line Lake McDonald's shore at Apgar, where the kids skip rocks while the motorhome waits on its long site back in the trees. The family rides the park shuttle up the Going-to-the-Sun Road, past the Loop and along the Garden Wall toward Logan Pass, with the valley filling the window and nobody in the group gripping a wheel. By evening everyone is back on the beach with dinner going, and the rig hasn't moved an inch.
Glacier runs this way for anything family-size because the Park Service keeps vehicles over 21 feet long, bumpers included, off the Sun Road between Avalanche Creek and Rising Sun. A motorhome can drive the lake stretch from West Glacier up to Avalanche, or the east end from St. Mary to Rising Sun, and the crossing over the top belongs to the shuttle, which the park runs as a ticketed pilot as of September 2026. Road and shuttle opening dates move from year to year, so check the Park Service's road status before you plan a day around the pass.
Apgar, Fish Creek and a hookup night at West Glacier
Apgar is the west side's big campground, spread through the trees at the foot of Lake McDonald, and it has real room for a big rig. By the Park Service's site lengths, its largest 25 sites take a rig up to 40 feet. Fish Creek, up the lake's north shore, has 18 sites at 35 feet and 62 more that stop at 27, while Avalanche, where the road limit begins, tops out at 26 feet and Sprague Creek takes no towed units.
Book the site first and the motorhome second. The cap on the pad you land decides between a 26-footer and something closer to 40, and summer sites in the park go early.
Nothing inside the park has hookups, so the lake nights are dry ones. The plug-in night is outside the gate at West Glacier, where the KOA has full-hookup pull-through and back-in sites with 50-amp service about 3 miles from the west entrance. It works as a first night when you roll in late and as a mid-week stop to fill water and empty tanks. For a base farther down the valley with town nights attached, the hookup parks around Whitefish and Kalispell work too.
St. Mary, Many Glacier and Two Medicine on the east side
The east side is its own leg of the week, reached around the south end of the park since the rig can't cross Logan Pass, and it feels like a different park once you get there. St. Mary Lake runs long below the road with Wild Goose Island in the middle of it, and Many Glacier puts the peaks straight up out of Swiftcurrent Lake.
The 40-foot sites are the scarce thing on this side. St. Mary has 3 of them and 22 more to 35 feet, Many Glacier has 13 sites at 35, and Two Medicine, in its own valley to the south, has 10 at 35.
For a hookup night, the St. Mary KOA, owned by the Blackfeet Nation, has full-hookup sites with 50-amp service. When the park's loops are full, Blackfeet campgrounds sit within a few miles of the east entrances, out where the prairie runs up against the mountains, and it's worth asking about site length when you book.
For two people who'd rather drive the Sun Road over the top themselves, a rig under 21 feet does it, and the east side from St. Mary is written up on Outwander's Montana page for smaller rigs.