Southern Arizona Public Lands Protection Act of 2018 This bill withdraws federal lands and interests located in Pima and Santa Cruz Counties, Arizona, as well as all federally owned subsurface interests under the administrative jurisdiction of the Bureau of Land Management (BLM) in lands in Pima County, from: (1) all forms of entry, appropriation, and disposal under the public land laws; (2) location, entry, and patent under the mining laws; and (3) operation of the mineral leasing and geothermal leasing laws, and the mineral materials laws. The bill also withdraws all federally owned interests in BLM lands in Pima County from entry, location, or patent under the general mining laws.