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
mountain 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.