St Mary Campground is the largest campground on the east side of Glacier National Park, located a half-mile from the St. Mary entrance and offering convenient access to Saint Mary Lake for fishing and paddling.

The campground features three loops with 142 total sites (tent and RV), flush toilets, potable water, and shower facilities, though amenities are limited to dry camping with no hookups.

Loop A prohibits generators for a quieter experience, while Loops B and C allow them; note that sites are relatively small and exposed with limited shade, and the campground fills quickly during peak season.