Vintage 1970's Yellowstone National Park Guide Booklets,
Yellowstone Trails, A Hiking Guide-1978 120 pages
Studies of Geysers & Hot Springs Along the Firehole River- 1978 54 pages
Earthquake! Yellowstone's Living Geology- 1976 62 pages
A Guide to Geyser Gazing- 1976 64 pages
(F-1)