Joe T. Fallinin Campground at Mackay Reservoir


Fishing at Mackay Reservoir

Fish Species and Mackay's History of Fishing
Today, Mackay Reservoir is stocked with rainbow trout and kokanee salmon. This has given it the reputation as one of the best ice-fishing lakes in the region. Here’s what you might find:

West Slope Cutthroat:
Black spots scattered on the front and back of the body, and on the back and tailfin. Also look for a red “cutthroat” mark under the lower jaw. 
 
 
Mountain Whitefish:
Shiny silver scales, small mouth on the bottom of the head, and a forked tailfin. Younger whitefish are often food for trout and salmon.
 
  
Brook Trout:
Watch for pink spots with blue halos on the sides of the fish, black lines on the pelvic and pectoral fins, and mottled dorsal fins.
 
 
Kokanee Salmon: 
Known as the “landlocked sockeye,” this fish stays its whole life in fresh water. Kokanee have a bluish-black top, silver sides, and a white stomach.
 
Rainbow Trout:
Look for small, irregular black spots on top of a pinkish-red stripe on their sides and on the tailfin.
 
 
 
 
Mackay's History of Fishing

When settlers first came to the area, few fish were found in the Big Lost River aside from the native whitefish. The Big Lost’s Stocking fish from milkcans circa 1920mountain whitefish population was isolated from other mountain whitefish between 165,000 and 340,000 years ago. This happened when the "sink drainages" of central Idaho became disconnected from ancient Lake Terreton and the Snake River. Sink drainages flow to the northern edge of the Snake River Plain and then flow underground. This isolation explains the subtle differences in appearance between the Big Lost whitefish and other similar species.
 
Trout were first introduced in 1889, when they were transported in barrels by pack horses from the Wood River. By 1918, the Big Lost River had become known as the best trout fishery in the state. Fishermen gave credit to the food-rich reservoir which helped fish to over the winter. 
 
By the 1920s, fishing had become an important economic asset to the Mackay area. President Warren G. Harding and his party toured Pocatello and Idaho Falls in June 1923. A dozen Mackay anglers “whipped the stream the night before with their flies and 500 rainbow trout were presented to His Excellency, as a gift and remembrance of the Lost River.” The Idaho Fish and Game built the river’s first hatchery upstream from here in 1925. This hatchery is still in operation today.
 
Fishing on the Big Lost River and Mackay Reservoir is a year-round sport today. Many fishing outfitters and sporting goods stores in Idaho advertise the outstanding fly fishing throughout the region. Hundreds of anglers brave the winter weather every year for a spot on the frozen reservoir. Fishing licenses are required, and are sold at several businesses in Mackay.