Clearwater Region Spring Chinook Update 6/2/2026

Spring Chinook Run Summary

Many folks have called, emailed, texted, or stopped by the office asking the same question: “What happened this season?” I will do my best to summarize the moving parts that shaped this year’s fishery.

Preseason forecasts are generated largely using jack return information from previous brood years. Broodstock needs are first subtracted from the forecasted return, and the remaining fish are then divided evenly between the sport and tribal harvest shares. For 2026, the preseason sport harvest share was projected at 2,009 adults for the Clearwater Basin and 1,923 adults for the Rapid River return. While these were considered moderate harvest shares, recent years had exceeded preseason forecasts, so fish managers entered the season optimistic about the opportunity this run could provide.

As Chinook move upstream through the Columbia River system, managers closely monitor conversion rates between dams. On average, 75% of Idaho-bound fish passing Bonneville Dam successfully reach Ice Harbor Dam. Once fish pass Ice Harbor Dam, managers typically expect about 95% of those fish to successfully pass Lower Granite Dam. Because of this historically high conversion rate, lower Snake River fisheries have generally had relatively limited impacts on Idaho fisheries, as managers collaboratively account for the small percentage of expected catch. Collectively, 74% of Idaho-bound fish counted at Bonneville Dam ultimately return to Idaho fisheries upstream of Lower Granite Dam.

Once fish pass Lower Granite Dam, Idaho fisheries are already underway, and managers begin refining harvest shares using the actual run size observed at Lower Granite rather than relying solely on preseason forecasts. Depending on the run strength, this can either increase or decrease the available harvest share during the season. IDFG also collects genetic samples at Lower Granite Dam to verify stock composition and ensure PIT tag data accurately reflects the proportion of each returning stock, including Clearwater, Rapid River, upper Salmon, and others.

What occurred this season has not been documented in the roughly 30 years IDFG has managed these fisheries under the current framework. Conversion rates between Ice Harbor Dam and Lower Granite Dam declined dramatically, dropping from the expected 95% to approximately 87%. That reduction substantially decreased the number of fish ultimately reaching Lower Granite Dam and, in turn, significantly reduced the available harvest share upstream in Idaho.

At face value, an 8% decline in conversion may not sound substantial. However, when applied to an already modest run size, relatively small percentage changes can have major impacts on available fishing opportunity and harvest allocation.

Early public concern understandably focused on whether lower Snake River fisheries exceeded their harvest shares. However, harvest accounting provided by individual fisheries managers did not fully explain the deficit observed at Lower Granite Dam. Other theories focused on spill operations and water management, though operational adjustments made during the migration period did not appear to improve conversion rates.

At this point, all co-managers are actively working together to better understand what occurred during this migration, identify where losses may have occurred, and determine what management or operational adjustments may help prevent similar issues in the future.

This season was frustrating for everyone involved; anglers, guides, tribes, and fisheries managers alike. Despite the difficult outcome, I appreciate everyone who participated in the fishery, provided feedback, and remained engaged throughout a very challenging season.

Clearwater Chinook Fisheries:

Based on the initial Chinook return over Bonneville Dam and early-season conversion rates, the Clearwater Basin entered the season with an estimated sport harvest share of 1,202 adults. Early indications suggested the run would stabilize and sustain that harvest share, so IDFG managers structured fisheries to meet those harvest objectives.

Harvest started relatively slow as fish first entered Idaho waters (see Clearwater harvest table below), but effort and success increased substantially during the fourth week of the season in the lower Clearwater River. That uptick in harvest, combined with a declining harvest share, resulted in the closure of the lower Clearwater fishery. The remainder of the Clearwater Basin stayed open four days per week with a 1-adult daily limit, at which time approximately 727 fish remained within the harvest share.