Big Arm State Park features a concrete boat ramp and dock on Flathead Lake's Big Arm Bay, serving as a popular launch point for boating and fishing activities.

The facility includes ample amenities such as a campground with 41 campsites, RV/trailer parking, showers, flush toilets, and bear-resistant storage lockers.

All watercraft must be inspected before launching, and a tribal fishing license is required for fishing on the southern half of Flathead Lake within the Flathead Indian Reservation.