we didn't stay there but Black Sandy State Park northeast of Helena gets good reviews. 50 amp electric. Potable water and no sewer. There are also several BLM campgrounds in the area but no hookups. There is also a KOA in Townsend.
Lonny & Diane
2004 Country Coach Allure 33' "Big Blue"
Towing 2008 Chev Colorado 4x4
Semper Fi