Sluice Boxes State Park is about as primitive as state parks get—there are no RV hook-ups, no firewood concessions, just a vault toilet near the trailhead and a warning to hikers: the 8 northernmost miles of Belt Creek Canyon that make up the park are undeveloped, steep, climatically unpredictable, and not much suited for fair-weather hikers.
Visitor access to the park is provided by the abandoned railway grade that once served the canyon's placer miners and prospectors. You'll have to ford Belt Creek, which is not something you want to try during spring runoff, so hikers generally tackle Sluice Boxes from mid-July through September, when the water is less pushy.
Unmaintained trails provide access to the creek for fishermen and adventurous floaters, who should be practiced and competent before messing with Belt Creek's cold, rocky flow.
Sluice Boxes features no developed campsites, and a backcountry camping permit is required of overnighters. Get permits from the FW&P office in Great Falls, at 406-454-5840 or 406-454-5857.