Idaho State Parks and Recreation Interpretive Sign: “Henrys Lake has been managed as a trophy fishery since 1976. Cutthroat trout, Idaho’s state fish, are native to Henrys Lake and are found naturally in more Idaho waters than any other trout or salmon. They are easy to identify – just look for the bright red ‘slash’ under their jaw. Steelhead and chinook and sockeye salmon are all ocean-going cousins of the cutthroat. The trout spawn in the spring but begin the journey to tributaries during late fall and early winter. Trout fry stay in the tributaries for a year before heading to the lake where they will live for about six years. Lake-dwelling cutthroat commonly grow to about 20 inches and can weigh as much as 20 pounds! Most of the cutthroat in Henrys Lake weigh three to five pounds.”
Idaho State Parks and Recreation Interpretive Sign: “Other species living in this lake include Rocky Mountain sculpin and mountain whitefish. Eastern brook trout, which average about 3 pounds, and rainbow-cutthroat trout hybrids weighing up to approximately 14 pounds are introduced species that also thrive in the lake. The state’s largest brook trout ever caught weighed 7.2 pounds and was caught here at Henrys Lake.”
Idaho State Parks and Recreation Interpretive Sign: “The North Fork Reservoir Company was created in 1916 as a nonprofit corporation. It supplies water from Henrys Lake to six canal companies in the St. Anthony area, irrigating about 47,000 acres of farmland. Farming and ranching are vital to eastern Idaho’s economy. Henrys Lake was dammed in 1923 which increased the size of the lake from 1,500 acre feet to 79,600 acre feet. The dam was rebuilt in 1964, increasing the lake’s capacity to 86,000 acre feet.”
Idaho State Parks and Recreation Interpretive Sign: “The lake level fluctuates little and is dependent upon irrigators’ needs and climactic changes, like prolonged drought. This constant elevation provides excellent fish habitat, and Henrys Lake is renowned for its world-class fishing. No local, state or federal money was used to create this reservoir. Instead, the farmers and ranchers who use the reservoir’s water funded the construction of the dam.”
Planning a trip soon? Use our links to get discounted tickets, rental cars, and more! Our site is partly supported by affiliate partnerships; your purchases through our affiliate links help support our site and the development of even more great content!
Other Wildlife at Henrys Lake
Henrys Lake Habitat Diversity
“Looking for Wildlife? Habitat Diversity Provides Homes for Many Wildlife Species. The Henrys Lake ecosystem is diverse enough to support a wide variety of wildlife. Please observe wildlife safely and from a distance by using binoculars or a spotting scope. Some species in the area can be dangerous if you approach too closely. Can you find and identify many of the common wildlife species in the area?”
Birds at Henrys Lake
The Great Blue Heron is the largest North American heron and can be found in fresh and salt waters.
Osprey talons are adapted to catch and hold fish.
The American Avocet is one of 18 species of shorebirds which migrate and/or inhabit this area.
The Bufflehead is the smallest diving duck.
The American White Pelican can eat 15 to 20 pounds of fish per day.
Before fall migration, Canada Geese lose their flying feathers, thus becoming grounded for a few weeks.
Red-tailed hawks are easily identified in flight by their broad red tail and its distinctive call, a harsh descending kerr.
The bugle of the sandhill crane is easily recognizable.
Bald eagles do not develop their distinctive white head until 4-5 years of age.
Mammals at Henrys Lake
Although clumsy looking, moose can run up to 35 miles per hour.
The slough is a great hunting ground for the red fox.
Pronghorns have strong, slim legs that make them faster than any other North American mammal.
The beaver can fell a willow the size of your arm in three minutes.
The distinctive call of the coyote keeps the band alert to the location of its members and reunites them when separated.”
Idaho State Parks and Recreation Interpretive Sign: “How was Henrys Lake Formed? Two ice ages existed in this area. The most recent, known as the Bull Lake Ice Age, occurred approximately 140,000 years ago and lasted about 50,000 years. During this time, glaciers formed on Sawtooth Peak (located behind you and to the left) and on Targhee Peak. When the glaciers melted, the water flooded this valley, forming Henrys Lake. Henrys Lake was probably formed about 9,000 years ago during the last ice age, at about the same time the Great Lakes were created in the northern United States. Those huge lakes were probably formed by moving sheets of ice while Henrys Lake was created by a mountain glacier that dammed the Snake River valley between the Henrys Lake Mountains and the Centennial Range.”
Idaho State Parks and Recreation Interpretive Sign: “You are standing on a ridge made up of rocks moved by water which is combined with glacial till, rocks which are broken and carried or pushed by the action of a glacier. This ridge does not support many trees since the glacial material does not retain water as well as other types of soil.”
Idaho State Parks and Recreation Interpretive Sign: “Signs of an Ancient Sea: Millions of years ago, before the ice ages, there was a large inland sea covering this area. If you look closely, you may see evidence of the ancient sea floor bottom by finding tiny crinoid fossils embedded in the limestone rocks along the trail.”
[…] Island Park, Idaho and Henrys Lake […]
[…] Island Park, Idaho and Henrys Lake […]