Natrona County administrative offices are located at 200 North Center Street, Casper, WY 82601; phone: 307-235-9200.
Natrona County was created in 1888 from part of Carbon County. The county is named for the natron deposits (hydrated soda ash) that were found in the area. Robert Stuart entered the region following a Crow Indian trail, planning to open a series of trading posts. His small party erected a hut in 1812 near Bessemer Bend.