Campgrounds and RV parks near Boulder, MT

Boulder Hot Springs is the main in-town attraction. The historic inn is on the National Register of Historic Places and offers day-use soaking, with an outdoor pool kept around 96 to 100 degrees Fahrenheit and indoor plunges at 103 to 106 degrees Fahrenheit, plus steam rooms. About an hour southeast, Lewis and Clark Caverns State Park is the region's headline day trip. The park protects one of the most highly decorated limestone caverns in the Northwest, with cave access by guided tour only, generally offered from May through September. Above ground the park has hiking trails, a visitor center, and picnic areas overlooking the Jefferson River valley. Other nearby options include the Elkhorn ghost town, Tizer Botanic Gardens near Jefferson City, Gates of the Mountains boat tours on the Missouri River, and fishing on the Boulder and Jefferson rivers.

The core camping season runs from late May through early September, with July and August the busiest weeks. Many public campgrounds in the region operate seasonally, and higher-elevation Forest Service and Bureau of Land Management sites in the Elkhorns and Boulder Mountains often stay snowbound into late May, with access roads to some dispersed areas remaining rough well into June. Shoulder seasons trade crowds for cooler nights. Late May and September bring lower demand, but overnight lows can dip below freezing. At Lewis and Clark Caverns State Park, hiking trails, rental cabins, and the campground are open year-round, but water is turned off from October 1 through April 30, so flush toilets, showers, drinking water, and the RV dump are only available during the warmer months. Winter is quiet. Most public campgrounds close or go primitive, while private RV parks along Interstate 15 and Interstate 90, including the two KOA locations, typically operate with reduced services. Boulder Hot Springs stays open year-round for soaking, which makes cold-weather stops worthwhile despite reduced camping infrastructure.

Expect a working-Montana feel rather than a resort atmosphere. Boulder is a small county seat, so groceries, fuel, and basic services are available but limited. Butte and Helena, each about a 30-minute drive, are the closest full-service supply stops for RV travelers. Site quality varies. Alhambra RV Park offers full-hookup sites with a quiet, shaded feel. Cardwell sits right off Interstate 90 with easy highway access, and check-in for the RV sites typically happens at the adjacent general store. Public forest campgrounds tend to be more rustic, with vault toilets, no hookups, and uneven pads. Cell service is generally solid along Interstate 15 and Interstate 90 but drops quickly on side roads into the Elkhorns and Boulder Mountains. Wildlife is active, so food and coolers should be stored securely. Summer thunderstorms can hit hard in the afternoon, and fire restrictions are common in late summer, so check current status before lighting anything.