Keep out old mines are dangerous.

Bibliographic Details
Corporate Author:	United States. Office of Surface Mining Reclamation and Enforcement
Format:	Government Document Book
Language:	English
Published:	Washington, DC : U.S. Dept. of the Interior, Office of Surface Mining, [between 2000 and 2009?]
Subjects:	Abandoned mines > Risk assessment > United States. Mine safety > United States.
Online Access:	https://purl.fdlp.gov/GPO/LPS56643

Available Online