Gibson Reservoir
Gibson Reservoir and GibsonDam on Sun River
Most years, this scenic reservoir provides seasonal fishing opportunities for wild rainbow trout in late spring and early summer. Oftentimes, by mid to late summer, Gibson is drawn down too low (sometimes more than 70 feet) to provide reasonable shore or boating access to anglers. Gibson is no longer stocked with fish, although rainbow trout and even coho salmon were stocked at one time. The reservoir fishery is currently sustained by wild rainbow trout produced in the forks of the Sun River above the reservoir and its tributaries. Rainbow trout do not grow very large in Gibson because the reservoir is relatively cold and deep and has dramatic water level fluctuations. These fluctuations make it impossible for productive shoreline habitats, including weedbeds, to develop. In lakes with stable water levels, these productive shoreline zones produce large numbers of aquatic insects and freshwater shrimp, which greatly stimulate trout growth. Rainbow trout in Gibson currently average just 11-inches long. Brook trout, Arctic grayling, white suckers, and mottled sculpins are also common in Gibson. The grayling originated from plants made in the North and South Forks of the Sun River above Gibson in 1999 - 2001 (see Arctic Grayling section).
Diversion Lake
Typical drawdown of GibsonReservoir in September 2004
Diversion Lake
This small reservoir, located about two miles downstream from Gibson Dam, is more like a slow spot in the Sun River than a reservoir or lake. Rainbow trout were historically stocked by FWP from 1933 through 1953, but this fishery is now sustained solely by natural reproduction. Other common species include rainbow-cutthroat trout hybrids, white suckers, mottled sculpins, and brook trout. A few Arctic grayling have been sampled in the river immediately upstream of the reservoir. These grayling originated from the plants made in the forks of the Sun River upstream from Gibson Reservoir.
Pishkun Reservoir
Pishkun Reservoir, along RockyMountain Front
The most diverse fishery in the Sun River drainage is found in Pishkun Reservoir. Pishkun was originally managed as a coldwater fishery and was commonly stocked with rainbow trout and occasionally with coho salmon and Arctic grayling. Stocking of these species eventually ceased after illegally introduced yellow perch and northern pike became established in the reservoir during the 1950s. In the following years, several different rainbow trout stocking strategies were attempted but were unsuccessful. Northern pike ate most of the stocked fish and few rainbow trout survived to provide a fishery. However, the rainbows that did survive grew to huge sizes. FWP tried stocking kokanee salmon into Pishkun for several years, but with limited success.
A large northern pike from Pishkun Reservoir
Management direction for Pishkun changed in 2003 when it was decided to experimentally reduce northern pike numbers to see if survival of yellow perch and rainbow trout could be improved, while maintaining a fishery for "trophy" pike. In other words, the idea is to create a more balanced fishery with better variety. Trapnets were used in 2003 and 2004 to remove northern pike during their mid-April spawning period. About 500 smaller pike were removed each year and the few larger, trophy-sized pike netted were released back into the reservoir. Most of the pike were small (average length of 18.4 inches) — called "hammer handles" by dedicated pike anglers . In 2004, captured pike were tagged, transported and released into nearby Split Rock Lakes to provide additional northern pike angling opportunities. This transfer program has been very successful. Anglers have reported good fishing and returned many tags from pike caught on Split Rock.
Transplanting pike to Split Rock Lake
Pike removal efforts will continue in Pishkun for another couple of years while biologists monitor the effectiveness of this program. It is hoped removing some of the pike from Pishkun will lead to better perch fishing, improved pike growth rates, and an opportunity to establish a rainbow trout fishery. Pishkun has abundant deep-water habitat, and in the past has produced trophy rainbow trout in the 10- to 12-lb range.
Fisheries technician Kelly Smithholds a 10 pound
rainbow from Pishkun Reservoir
More than 150,000 surplus rainbow trout were stocked into Pishkun in 2003 because drought conditions reduced stocking needs elsewhere. Future plans include stocking larger (8-inch) rainbow trout in the fall when cooler water temperatures will hopefully make them less likely to be eaten by pike.
Willow Creek & Nilan Reservoirs
An important destination for both open water and ice fishermen, Willow Creek Reservoir is one of the most popular fisheries in the Sun drainage. Only the Sun River itself receives more fishing pressure. Annual stockings of about 70,000 fingerling (3-5 inch) rainbow trout sustain this popular fishery located about five miles north of Augusta, and these stocked fish grow quickly. Shore anglers enjoy excellent fishing success for rainbow trout in the spring and fall, while boat anglers enjoy good success most of the year except during the warmest periods in late summer. Other species present in Willow Creek Reservoir include rainbow-cutthroat trout hybrids, brook trout, and white suckers.
Willow Creek Reservoir, in Sun River drainage near Augusta, MTRainbow trout fishing is also excellent in Nilan Reservoir, located eight miles west of Augusta. FWP annually stocks about 80,000 fingerling rainbows into Nilan, and these fish grow very quickly in this productive reservoir. Nilan Reservoir is especially popular with fly fishermen and it is common to see many float tube anglers on this reservoir during the spring and early summer months. Brown trout and white suckers are also present in this reservoir.
