The Territory of Utah was organized September 9, 1850, its area being a part of that acquired from Mexico by the United States in 1848. As originally organized it extended from the summit of the Rocky Mountains in central Colorado westward to the east boundary of California, including all the territory between the parallels of 37° and 42° north latitude. These limits are thus defined in the act creating the Territory:

All that part of the territory of the United States included within the following limits, to wit: Bounded on the west by the State of California, on the north by the Territory of Oregon, and on the east by the summit of the Rocky Mountains, and on the south by the thirty-seventh parallel of north latitude, be, and the same is hereby, created into a temporary government, by the name of the Territory of Utah.

The organization of Colorado Territory, in 1861, reduced it on the east to its present eastern boundary, and the formation of the Territory of Nevada, in the same year, reduced it on the west to the meridian of 39° west of Washington. The enabling act of the State of Nevada, passed in 1864, moved the west boundary of Utah a degree farther east, placing it upon the meridian of 38°, and upon the admission of Nevada as a State, in 1866, Utah was still further diminished and Nevada increased, the eastern boundary of the latter being placed upon the meridian of 37° west of Washington. Meantime, in 1863, the northeast corner of the State was cut off and added to the Territory of Idaho, and in 1866 a square degree in the northeast was added to the Territory of Wyoming, thus reducing Utah to its present dimensions. On January 4,1896, it was admitted as a State, its boundaries being the same as those of the Territory of Utah, as follows:

Commencing at the intersection of the forty-first parallel of north latitude with the thirty-second meridian west of Washington; thence south on this meridian to the parallel of 37° north latitude; west on this parallel -to the thirty-seventh meridian west of Washington; north on this meridian to the parallel of 42° north latitude; east on this parallel to the meridian of 34° west of Washington; thence south to the forty-first parallel of latitude, and east on this parallel to the place of beginning.

The area of the State is 84,970 square miles, of which it is estimated that 2,780 square miles are water surface, including Great Salt, Utah, and other lakes, and 82,190 square miles are land surface.