Step upstairs from the 1920s log Brownie’s Market (406/226-4426, May–Sept., $15 dorm bed, $31 private room) to find a charmingly decrepit youth hostel with sloping linoleum floors and lots of old photos and books in the sleeping rooms.
Backpackers Inn (406/226-9392, May–Sept., $10) also offers dorm accommodations (bring your own sleeping bag) in cabins behind Serrano’s Mexican Restaurant [1]. The cabins face onto a pleasant grassy yard.
Links:
[1] http://www.moon.com/destinations/montana/glacier-national-park/east-glacier-and-vicinity/food