The deluxe Earthquake Lake Visitor Center (Hwy. 287, 406/682-7620, 8:30 a.m.–6 p.m. daily, June–Sept., $3 per car) sits above Quake Lake [1]. The Hebgen Lake Ranger Station (406/823-6961) is actually on the northern edge of West Yellowstone.
Links:
[1] http://www.moon.com/destinations/montana/the-missouri-headwaters-and-south-central-montana/three-forks-and-the-madison-river-valley/quake-lake-and-h