JUNEAU, Alaska (AP) — A federal agency has questioned the validity of permits for a coal mine in south-central Alaska.

An official with the federal Office of Surface Mining told the state Department of Natural Resources, in a letter dated last week, that information it has received regarding permitting for the Wishbone Hill Mine has “significant gaps.” Kenneth Walker, manager of the Denver Field Division for OSM, asked the department, or DNR, to review its permit file and to let the office know if additional information is available.