Henry's Lake

Henrys Lake
Aerial view Courtesy of Idaho Tourism
Location	Fremont County, Idaho, United States
Coordinates	44°38′38″N 111°24′22″W / 44.644°N 111.406°W / 44.644; -111.406Coordinates: 44°38′38″N 111°24′22″W / 44.644°N 111.406°W / 44.644; -111.406
Primary outflows	Henrys Fork
Basin countries	United States
Max. length	4 mi (6.4 km)
Max. width	2 mi (3.2 km)
Surface area	8 sq mi (21 km2)
Average depth	2–9 ft (0.6–3 m)
Surface elevation	6,472 ft (1,973 m)

Henrys Lake is a small, shallow alpine lake, approximately 8 square miles (21 km²) in area, at 4 miles (6.4 km) in length and 2 miles (3.2 km) in width. It is located at 6,472 ft (1,973 m) above sea level in the mountains of southeastern Idaho in the United States. It is on the southwest side of the Henrys Lake Mountains of northern Fremont County, approximately 2 miles south the continental divide along the Montana state line, just west of Targhee Pass. It is 16 miles due west of the western boundary of Yellowstone National Park. The lake is located in Caribou-Targhee National Forest. Springs are found around the shoreline at Staley Springs, Pintail Point, Kelly Springs, the Cliffs, and along the northshore of the lake. Inlets are found at Timber Creek, Targhee Creek, Howard Creek, Duck Creek, Hope Creek, and Kenny Creek. The lake provides the headwaters of the Henrys Fork, a tributary of the Snake River. The lake lies less than 10 miles (16 km) across the continental divide from the headwaters of the Missouri River in southwestern Montana.

A dam built at the outlet of Henrys Lake in 1923 dramatically increased the surface area of the lake.

The 'official' Continental Divide Trail skirts around Henry's Lake. Many north bound thru hikers opt out of this section when leaving Yellowstone National Park and entering the Centennial Mountain Range in Idaho.

Henrys Lake is a popular destination for sport fishing. The most common species in the lake is Yellowstone cutthroat. They make up 55 percent of the trout population. The average size in 2015 was 15 inches but biologists found some fish over 20 inches. The second most prevalent species is rainbow-cutthroat hybrids, which make up 24 percent of the population. The average size is 19 inches, although Idaho Fish and Game found hybrids longer than 25 inches. Brook trout make up 21 percent of the population. The average length is 16 inches but biologists found several Brook trout that exceeded 20 inches in length. There is a fish hatchery on the north side of the lake that helps to replenish the lake.