Priest Lake Decision Guide
Prior to developing the current statewide Fisheries Management Plan (2013-2018), Idaho Fish and Game (IDFG) staff received many public comments wanting to manage fishing at Priest Lake differently. While many anglers were satisfied with the fishery, others wanted a different type of fishery. In particular, restoring the Kokanee fishery was a popular suggestion. IDFG staff also faces ongoing challenges to manage Priest Lake mainly as a Lake Trout fishery, while also working to conserve native fish (Bull Trout, Westslope Cutthroat Trout) in Upper Priest Lake. Lake Trout move freely between both of these connected lakes, making it hard to be successful at conserving native trout species in the upper lake.
Public comments collected in 2012 showed opinions on Priest Lake fishery management were mixed. As a result, the 2013-2018 Fisheries Management Plan did not recommend a different management strategy. Instead, it set the direction to learn more about the Priest Lake fishery and to more actively engage with anglers interested in the fishery. IDFG has been studying Priest Lake and Upper Priest Lake over the past several years. We finished a Lake Trout population dynamics study, increased Kokanee monitoring, started studying the Westslope Cutthroat Trout population, and finished a year-long angler creel survey. IDFG also formed the Priest Lake Fishery Advisory Committee in 2013. Thirteen members from the community joined to represent a variety of views about managing the fishery. The Committee is helping IDFG develop the Priest Lake portion of the upcoming 2019-2024 Fisheries Management Plan. The group has met regularly for nearly four years and recently developed a list of three separate management alternatives for the public to consider.
The Historical Fishery
Priest Lake
Historically, fishing on Priest Lake was for native Westslope Cutthroat Trout, Bull Trout, and Mountain Whitefish. Historical accounts suggest the lake was famous for its Cutthroat Trout fishing in the early 1900’s. Since that time, several changes in the lake and surrounding landscape have influenced the fishery. Lake Trout were introduced in the 1920’s, and Kokanee arrived in the late 1940’s. These species added both new fishing opportunity and threats to native species. Road building and timber harvest in the surrounding area during the early- to mid-1900’s also impacted native fish by reducing the quality of stream habitats where spawning and early rearing occur. Together, these changes lowered the populations in Cutthroat Trout and Bull Trout.
By the 1950’s, Cutthroat Trout and Bull Trout fishing was only a small part of the Priest Lake fishery, and most anglers were after Kokanee. Even though Lake Trout and Bull Trout fishing was a minor part of the Priest Lake fishery in the 1950’s and 1960’s, they were a popular trophy component. Lake Trout and Bull Trout grew large on a diet of abundant kokanee. In the mid-1960s, Mysis shrimp were introduced to provide more food for Kokanee. Instead, Mysis shrimp boosted Lake Trout survival and competed with Kokanee for food. Moving into the 1970’s, the Lake Trout population began to grow while Kokanee numbers rapidly dropped. By the late 1970’s, Kokanee fishing had declined dramatically and anglers switched their focus mostly to Lake Trout. Throughout the 1980’s, 1990’s, and early 2000’s, Priest Lake remained mostly a Lake Trout fishery, although the average fish size steadily declined from the lack of Kokanee as a food supply. Low Kokanee numbers during this period led to closure of angler harvest. Cutthroat Trout angling remained a minor component of the fishery. Bull Trout, heavily impacted by a growing abundance of Lake Trout, were mostly gone from the lake. Harvest of Cutthroat Trout and Bull Trout was closed in the 1980’s to protect the remaining populations.
Upper Priest Lake
Upper Priest Lake supports the same species as the main lake and fishing historically focused on Cutthroat Trout, Bull Trout, and Mountain Whitefish. An open channel called the Thorofare connects Upper Priest Lake and Priest Lake and allows fish to move between the lakes. As a result, changes in the Priest Lake fish community over time have also influenced Upper Priest Lake. It did take longer for introduced species to establish in Upper Priest Lake, thus it remained more of a stronghold for native species. Lake Trout were only rarely found in Upper Priest Lake through the 1970’s and 1980’s, but became established in moderate numbers by the mid 1990’s and became a greater threat for native species.
Today’s Fishery
Priest Lake
Priest Lake is currently managed with a focus on opportunities for anglers to harvest Lake Trout. Catch-and-release fishing for native Cutthroat Trout and limited harvest opportunity for quality-size Kokanee are also important. Smallmouth Bass are relatively new to Priest Lake and are not a management focus, but they do provide good fishing opportunity.
Lake Trout are abundant in Priest Lake and catch rates are usually good. The average Lake Trout size (15”-25”) in the lake has declined over the last few decades because of lower growth rates. Kokanee, once abundant in Priest Lake, were the primary food for Lake Trout to grow to trophy sizes. Lake Trout now eat mostly Mysis shrimp, so growth rates are much slower with smaller average sizes. Trophy Lake Trout still occur, but are much less common than they once were.
Kokanee are a popular species for Priest Lake anglers, but catch rates are low compared to other Kokanee lakes in the region because of their low numbers. Kokanee fishing in Priest Lake was re-opened in 2011 after being closed for many years. Kokanee numbers change yearly, but have remained very low relative to the peak in the 1950’s and 1960’s. Generally, Kokanee in Priest Lake are large (14 + inches).
Native Bull Trout and Westslope Cutthroat Trout historically supported the Priest Lake sport fishery. Anglers targeting Cutthroat Trout experience good catch rates, but only catch-and-release angling is allowed. Bull Trout are now rare in Priest Lake and do not support a fishery.
Upper Priest Lake
Upper Priest Lake is currently managed with a focus on conserving native fish, including Cutthroat Trout and Bull Trout. Stable populations of both species are found in the lake. Lake Trout are actively removed from Upper Priest Lake yearly to lower their impact on native fish. Movement of fish, including Lake Trout, through the connection between Upper Priest Lake and Priest Lake makes it nearly impossible to keep Lake Trout out of the upper lake. However, stable to increasing Bull Trout and Westslope Cutthroat Trout numbers in Upper Priest Lake and in spawning tributaries suggests removing Lake Trout has helped native fish conservation. Good catch-and-release fishing for both Cutthroat Trout and Bull trout exists in Upper Priest Lake, while liberal harvest of Lake Trout is encouraged.