Federal law enforcement agencies include - http://en.wikipedia.org/wiki/Federal_law_enforcement_in_the_United_States - security for Coast Guard bases seems to be missing - I suspect that 1 or 2 of the larger USCG sites have their own security or police - specifically the air stations, the USCG Academy, maybe USCG HQ also (wherever that is)
West of the Mississippi River, much of the rural land is owned by the federal government. The mountainous forests are administered by the US Forest Service for recreational and logging uses. The rangelands are administered by the Bureau of Land Management for recreation, ranching, and oil exploration. The most scenic areas are administered by the National Park Service. Marshlands and tundra areas (in Alaska) are typically encompassed by National Wildlife Refuges operated by the US Fish & Wildlife Service. The Bureau of Indian Affairs jointly operates many Indian Reservations with local Indian Tribes. All of these agencys provide wildfire control services. Just the National Park Service provides structural fire fighting, ambulance, and police services.
There are also some large military and energy sites in the western USA. Hanford DOE, Los Alamos DOE, White Sands Missile Range, Vandenburg Air Force Base, Camp Pendleton, Camp Irwin, are some of the larger sites. Each site typically provides its own public safety resources for the protection of its workers, tenants, residents, and guests.
https://sites.google.com/site/usforestserviceusa/ - US Forest Service
https://sites.google.com/site/usfsradiofreqs/ - United States Forest Service radio systems information
http://www.iafc.org/associations/4685/files/ems_NISTdeploymentReportEMS.pdf - NIST EMS Deployment study - Sept 2010
http://www.fcc.gov/pshs/services/911-services/enhanced911/psapregistry.html - FCC PSAP Registry