TY  - RPRT
TI  - Recreation impacts to cliff resources in the Potomac Gorge: Final report, June 2011
AU  - Jeffrey L. Marion
AU  - C. Carr
AU  - C.A. Davis
PY  - 2011
UR  - https://pubs.usgs.gov/publication/70004877
ID  - 70004877
ER  -