Ririe Reservoir’s kokanee population is undergoing a dramatic seasonal transformation. Male fish are shifting from silver to striking red hues as the annual spawning cycle accelerates, signaling that anglers have a limited window to pursue the colorful salmon before conditions become unfavorable for fishing.
The reservoir’s water level has dropped significantly in recent weeks. Docks at the Blacktail access point have already been removed due to low water, leaving Juniper Campground as the sole remaining boat launch on the reservoir. A prominent rock island near Juniper is now visible above the waterline—a marker of how rapidly the reservoir has emptied. According to Bob Johnstone, the Juniper Campground manager, the situation will worsen. “As fast as they are taking water out of Ririe, the water will soon be too low to launch boats here,” he told the outlet that first reported this story, as first reported by the EastIdahoNews.com.
Despite the declining water conditions, fishing remains productive. A recent outing yielded 16 kokanee in a single morning session, with the first cast producing a 16-inch male that had already begun its color transition and was caught on garlic-flavored corn. The angler’s previous week of fishing had resulted in a catch limit, predominantly composed of large, light pink males caught within two and a half hours of sunrise.
Seasonal Color Change Underway
Male kokanee at Ririe have been noticeably shifting color for approximately three weeks. The transformation follows a predictable pattern: males initially turn pink, then gradually assume deeper red tones as their bodies absorb silver scales. Within roughly four more weeks, the male kokanee bodies will begin breaking down as the spawning cycle reaches its conclusion.
The reservoir supports two distinct kokanee populations with different spawning timelines. The red males currently being caught display bright red flesh, indicating they are an “early-spawn” species. The silver-colored males and females, by contrast, show orange or yellow flesh, identifying them as “late-spawn” fish, as first reported by the EastIdahoNews.com. The colored red males are part of the 2024 stocking effort, which introduced 76,000 three-to-six-inch fingerlings that have now grown to 16–18 inches. The larger silver males and females likely originated from the 2023 stocking, when 254,000 fry of late-spawning kokanee were planted in the reservoir.
The most recent stocking occurred on May 19, introducing 179,000 fingerlings and 144,000 sockeye fingerlings. Those 2025 stocking kokanee are now measuring 8–12 inches in length, still too small to target most anglers but growing steadily.
Wildlife Activity and Fishing Window
The spawning activity is drawing considerable attention from raptors. Eight to ten ospreys are feeding on fish each morning at sunrise, targeting smaller specimens in the 6–7 inch range. Bald eagles have also been observed in the area, attempting to steal fish from the ospreys—a testament to the abundant forage base the kokanee fishery supports.
Ririe Reservoir operates as a put-and-take kokanee fishery, relying entirely on regular stocking to maintain populations. The combination of falling water levels and approaching spawning decline suggests anglers have roughly two months of viable fishing remaining. Johnstone’s estimate indicates the Juniper launch will likely become unusable within approximately two weeks, depending on how quickly water levels continue to drop.
What Comes Next
Fishing enthusiasts hoping to experience Ririe’s kokanee run should prioritize trips in the coming weeks. Early morning departures, particularly around sunrise, offer the best chance of connecting with both the colorful spawning males and the more abundant silver females. Once water levels drop further and the Juniper launch becomes inaccessible, fishing opportunities at Ririe will effectively end for the season. Anglers should monitor current conditions before launching and be prepared for rapidly changing water access throughout September.