This is a list of counties in Utah.

Utah county boundaries

1. Beaver County formed in 1856.
2. Box Elder County formed in 1856.
3. Cache County formed in 1856.
4. Carbon County formed in 1894 from part of Emery County.
5. Daggett County formed in 1918 from part of Uintah County.
6. Davis County formed in 1852.
7. Duchesne County formed in 1915 from Wasatch County.
8. Emery County formed in 1880.
9. Garfield County formed in 1882 from part of Iron County.
10. Grand County formed in 1890 from part of Emery County.
11. Iron County formed in 1852.
12. Juab County formed in 1852.
13. Kane County formed in 1864 from part of Washington County.
14. Millard County formed in 1852 from part of Iron County.
15. Morgan County formed in 1862.
16. Piute County formed in 1865 from part of Beaver County.
17. Rich County formed in 1868 from part of Cache County. Known as Richland County until 1868.
18. Salt Lake County formed in 1852. Known as Great Salt Lake County until 1868.
19. San Juan County formed in 1880 from parts of Kane County, Iron County, and Piute County.
20. Sanpete County formed in 1852.
21. Sevier County formed in 1865 from part of Sanpete County.
22. Summit County formed in 1854.
23. Tooele County formed in 1852.
24. Uintah County formed in 1880.
25. Utah County formed in 1852.
26. Wasatch County formed in 1862.
27. Washington County formed in 1852.
28. Wayne County formed in 1892 from part of Piute County.
29. Weber County formed in 1852.

Source: Utah County Formation Chart (http://archives.utah.gov/referenc/utcolist.htm)