Dworshak Reservoir 2024 Fisheries Forecast

Dworshak reservoir will provide excellent fishing opportunities once again in 2024. Kokanee anglers should see improved opportunities from 2022-23, and smallmouth bass anglers should continue to experience excellent bass fishing with trophy opportunities. Higher abundances of rainbow trout stocking will also continue to provide opportunities for both boat and shore anglers.

Kokanee

For Dworshak kokanee anglers, 2023 was better than 2022 but was still not a banner year. There have been record high numbers of kokanee in the system since 2021 causing growth rates to be very slow. Most kokanee in Dworshak spawn at two years of age, and these are the fish that anglers typically catch. In 2023, annual surveys found the average length for a two-year-old kokanee was 8.5 inches. Although relatively small, this represented a one-inch increase from 2022. Past surveys have found that kokanee are difficult to catch until they exceed 8 inches, and anglers were much more successful catching these kokanee in 2023 than in 2022. 

Although Dworshak kokanee typically spawn at two years of age, they have been found to delay maturity until three when growth rates are slow. Given that two-year-old kokanee were the smallest on record in 2022, it was not surprising when we found a high abundance of three-year-old kokanee in 2023. Unfortunately, these three-year-olds were about the same size (~ 8.5 inches) as the two-year-olds. This makes sense biologically because it is typically the slowest growing fish that won’t spawn until they are three.

Based on last summer’s annual survey, we expect kokanee abundance to decline in Dworshak. The extremely abundant year-classes that hatched in 2020-2021 are beginning to age out of the population. The fish that were born in 2022 are more average in abundance and will provide a moderate abundance of two-year-old kokanee to fish for this year. The decline in kokanee abundance should contribute to faster growth rates, and I expect anglers will start to encounter 10-11 inch kokanee by the peak summer fishing months in 2024. I’ve already received a few reports from winter anglers catching good numbers of kokanee in the 9-9.5 inch range.

Results from our 2023 annual survey also indicated low numbers of age-0 kokanee. We estimated the number of age-0 kokanee in the reservoir was only about 250,000, which is the lowest amount we’ve seen since 1996. This isn’t entirely unexpected—kokanee populations tend to boom and bust. When they are extremely abundant, they often have poor reproduction, probably because spawners are smaller which means they dig shallow, lower quality nests, and produce less and smaller eggs. The positive side of this low production is that it should lead to much faster growth rates, and we expect that by 2025 Dworshak will likely have 12-13 inch kokanee again.

Smallmouth Bass

The Dworshak smallmouth bass population continued to thrive in 2023. The abundant kokanee population has benefitted Smallmouth Bass for a couple of reasons. First, lots of kokanee simply means lots of food for bass. 

Additionally, the high kokanee numbers have led to smaller-sized kokanee and that means there is more food available to small bass, not just the ones that are already big. In Dworshak, smallmouth typically grow relatively slow until they reach 12 inches. Once they get past that size they grow as fast as anywhere in the world. Over the last couple of years, the bass that were already a good size have gotten huge, and lots of bass that were “stalled” out around 11-12 inches have gotten past that bottleneck and are now also growing to a very good size. 

In 2023, anglers continued to find world-class trophy opportunities with 6-8 pound smallies once again being a regular occurrence.

Additionally, the amount of “quality” bass in the 2-4 pound range was excellent. This is because the high kokanee abundance has allowed many fish to grow into those sizes very quickly. 

The high numbers of bass that have grown to quality and trophy size over the last couple of years will lead to very good bass fishing on Dworshak again in 2024. As kokanee abundance declines over the next couple of years, so will growth rates of younger, smaller bass. Although trophy opportunities will remain, the number of quality fish in the 2-4 pound range will likely decrease over the next few years because of slower growth rates.

Rainbow Trout

Kokanee and smallmouth get the most attention on Dworshak, and for good reason. One additional opportunity that anglers should be aware of is rainbow trout. Catchable-sized rainbows are stocked from May through October at the Dent Acres boat launch. 

They distribute well throughout the reservoir, especially on the lower end below Dent bridge. Anglers often encounter these trout in creek mouths or when trolling for kokanee, but they can also provide an opportunity for shore anglers, especially at the main campgrounds including Dent Acres and Dworshak State Park. After spending the winter in the reservoir, the flesh quality of these fish can be quite good. Check out the upcoming stocking schedule for the Clearwater region here.