TY  - RPRT
TI  - Map showing relative ease of excavation of geologic units in the Henrys Lake Quadrangle, Idaho and Montana
AU  - I. J. Witkind
PY  - 1972
DO  - 10.3133/i781g
UR  - https://pubs.usgs.gov/publication/i781G
ID  - i781G
ER  -