Horse Mesa Dam

Horse Mesa Dam
Horse Mesa Dam.jpg
CountryUnited States
LocationTonto National Forest, Maricopa County, Arizona
Coordinates33°35′27″N 111°20′38″W / 33.59083°N 111.34389°W / 33.59083; -111.34389Coordinates: 33°35′27″N 111°20′38″W / 33.59083°N 111.34389°W / 33.59083; -111.34389
Construction began1924
Opening date1927
Owner(s)U.S. Bureau of Reclamation
Dam and spillways
Type of damConcrete thin arch
ImpoundsSalt River
Height305 ft (93 m)
Length660 ft (200 m)
Width (crest)8 ft (2.4 m)
Width (base)57 ft (17 m)
Dam volume162,000 cu yd (124,000 m3)
SpillwaysGated concrete tunnel and over-the-crest
Spillway capacity150,000 cu ft/s (4,200 m3/s)
CreatesApache Lake
Total capacity245,138 acre⋅ft (0.302373 km3)
Catchment area5,842 sq mi (15,130 km2)
Surface area2,656 acres (1,075 ha)
Normal elevation1,919 ft (585 m)
Power Station
Turbines3x 112/3MW units, 1x 97MW pumped-storage unit
Installed capacity129 MW

The Horse Mesa Dam is a concrete thin arch dam located in the Superstition Mountains, northeast of Phoenix in Maricopa County, Arizona.

The dam is 660 feet (200 m) long, 300 feet (91 m) high and was built between 1924 and 1927. The dam includes three conventional hydroelectric generating units totaling 32 megawatts (MW) and a pumped-storage unit with a capacity of 97 MW.

The dam and associated infrastructure were listed on the National Register of Historic Places in 2017.

A few homes are nearby for temporary employee housing. Its name is derived from when sheep-herders used to graze their saddle and pack animals on the mesa when they were driving their flocks through the area.[1] It has an estimated elevation of 2,067 feet (630 m) above sea level.


The dam forms Apache Lake as it impounds the Salt River. The dam and reservoir are located downstream from the Theodore Roosevelt Dam, and upstream from the Mormon Flat Dam.

Downstream view of Horse Mesa Dam.
Water flowing out of a spillway at Horse Mesa, circa 1940
Salt River below the dam.


  1. ^ Barnes, Will Croft (2016). Arizona Place Names. Tucson: Arizona Place Names. p. 211. ISBN 978-0816534951.

External links

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