National Archives Catalog is an online database of historical state and federal documents. Here you will find various things like maps and images.
Arizona Memory Project from the Arizona Library is a digital archive of historical documents about Arizona's past. It contains everything from old legislation and territorial maps to newspaper archives and photographs. It is the go-to place for anything "historical Arizona."
Mine and mineral information
The Diggings is a free online resource for current, past, and potential mining activity on BLM public land.
Plant and wildlife information
Catalog of Life for more information on Plants, animals, bacteria, etc.
Fish Base for information on all types of fish species.
National Geographic Animal Index for more detailed information on animals.
BirdLife International for information on birds.
Miscellaneous
Ultimately you should contact the land management agency to confirm.
Organizations
American Mining Rights Association Fights to keep roads open for mining and recreation and other issues facing the mining community.
Natural Restorations works with the National Forest Service to clean up our forests.
Tonto Recreation Alliance (TRAL) helps promote open access to the Tonto Forest. Additionally, TRAL helps maintain a network of 4x4 trails, and they also host trash cleanups.
Cell phone towers
CellMapper.net will show cell phone towers on a map. Pick your carrier, choose your network, and find the towers approximate location.