Fort Union, historically Union, is a major commercial area and an early settlement in the Salt Lake Valley of Utah that is now split between the municipalities of Midvale, Cottonwood Heights, and Sandy. The fort after which the area was named was built early in the Salt Lake Valley's post-1847 history at a strategic point where escarpments on either side of the Little Cottonwood Creek valley create a narrow gateway to the upper valley and Little Cottonwood Canyon beyond.