WEST GLACIER, MONT. – Campgrounds at Glacier National Park begin transitioning to primitive status in early September. When campgrounds are in primitive status NO water is provided. Any water taken from streams or lakes requires treatment before use. Primitive and winter front-country campgrounds include pit toilets, no running water and only a limited number of sites.
Winter camping is available at St. Mary and in the Apgar picnic area from December 1 through the night of March 31. There is no fee for winter camping; however, a valid entrance pass is required.
Get transition status for all Glacier campgrounds
The RV Handbook: Essential How-to Guide for the RV Owner, 3rd Edition

