Chart of County Formation in Utah

The first Mormon pioneers in Utah established several counties near the Great Salt Lake under their provisional government known as the State of Deseret. Utah Territory was created in 1851, and the first territorial legislature met from September 1851 to March 1852. The first territorial legislature formally re-created several counties begun by the State of Deseret. New counties also were created by the territorial legislature in that and later sessions. Boundaries were subject to frequent change, often as the result of forming other counties in Utah or other territories such as Nevada and Idaho from land initially in Utah Territory. Remote counties were often organized later than first created, and counties with low populations were often attached to others for political represenation. Counties formed after 1913 were not created by legislation, but by popular election and gubernatorial proclamation.

This chart shows the date of initial creating legislation for the various counties, the parent county if the county specifically was split from an existing county, cited legislation (from the Laws of Utah) or other action, and the current county seat.

Some of the following counties were abolished over the years or became parts of other counties or territories.

Extinct Counties