number of exclusive facts about amazing american river spring steelhead

Fish counts

Estimates of the historical American River spring steelhead run are available. Prior to construction of Folsom and Nimbus dams, counts of adult steelhead were made at the Old Folsom Dam. Although the number of fish counted was small, the majority (81%) of steelhead were counted during the months of May and June. 

In 1956, James A. Hinze, the first manager of the Nimbus Fish Hatchery, prepared the hatchery annual report. He wrote some steelhead passed the city of Folsom every month of the year except August and September. The peak of the run occurred in May or June. Later, the California Department of Fish and Game in their 1990 Central Valley Salmon and Steelhead Restoration and Enhancement Plan reported “American River spring-run steelhead was extirpated and the fall-run steelhead, which provided a fishery beginning in September in the American River, was severely decimated by Nimbus Dam”.

Dam construction

After construction of the two dams, federal and state mangers envisioned a fish hatchery was needed. The hatchery was to replace a lost run of approximately 19,000 Chinook salmon and an unknown number of steelhead. The 1953 contract indicated the hatchery be built to “compensate for the loss of said spawning habitat”. And it would have a capacity of 30 million eggs, and ultimately, if necessary, 50 million eggs. At that time, steelhead runs in the Sacramento River (excluding the American and Feather rivers) were estimated to range from 14,000 to 26,000 fish.

During the 1955 through 1957 seasons, Nimbus Fish Hatchery personnel trapped steelhead trapped from the American River. These first fish were sometimes trapped in late December and as late as the end of June. Most fish were spawned in March and April. Hatchery reports indicated American River female steelhead produced a higher average number of eggs than smaller Sacramento River steelhead. This suggested the early American River steelhead were physically larger than Sacramento River steelhead. However, due to the small number of eggs collected, winter steelhead eggs were transferred to the hatchery. In 1958-1959, eggs from Snow Mountain Egg Collection Station on the Eel River were transferred to the hatchery. Approximately 2 million juvenile fish from these transfers were eventually released in the American and Sacramento rivers.

Fishing opportunities

One early goal of the Department’s American River steelhead management was to “increase the proportion of the annual steelhead run entering the hatchery during the fall”. This was to enhance fishing opportunities. As part of this effort, steelhead eggs from Coleman National Fish Hatchery and summer steelhead from the N.F. Washougal River, Washington and were transferred to Nimbus Fish Hatchery from 1970 through 1981. In addition, in the early 1970’s, adult steelhead were trapped in the Sacramento River. Occurring upstream from the confluence of the American River near Interstate Highway 80 Bridge and transported to Nimbus Fish Hatchery.

About 1.6 million juvenile fish were subsequently released in the American and Sacramento rivers as part of this effort. The attempt to develop an early steelhead fishery in the American River was eventually discontinued. This was due to poor success holding early arriving adult steelhead at the hatchery. In addition, steelhead eggs from Mad River and Warm Springs hatcheries during the period 1978-1991, were transferred to the hatchery. The progeny were released in the American and Sacramento rivers. Since then, no out-of-basin steelhead eggs or fish have been transferred to the hatchery.

Genetic analysis

Based on genetic analysis, the Nimbus Fish Hatchery winter steelhead broodstock cluster with samples from northern California populations. They are most similar to winter steelhead from the Eel River. Researchers also report naturally spawned juvenile fish in the river are similar to the hatchery stock. Apparently, the Eel River winter steelhead stock has been most successful at adapting to the altered river environment. Since 1999, the progeny of all steelhead released from California fish hatchery have been marked by removing the adipose fin. Small trout caught from the American River with an adipose fin mark are likely fish released from Nimbus Fish Hatchery. Unmarked fish may be naturally produced fish or strays from the Sacramento River. 

“Bluebacks”

For several years’ anglers have reported catching steelhead from the American River during March and April. Most of these fish have been from 12 to 20 inches in length. However, some anglers have reported catching steelhead as large as 6 pounds. Some local anglers refer to these late steelhead as “bluebacks”. The origin of the name is also unclear. Blueback has been used to describe several different species of salmon and trout in various reports. 

In the late 1800’s, sockeye salmon Oncorhynchus nerka were referred to as Bluebacks, or Blueback salmon in federal reports. The fish were taken in the Columbia River commercial fisheries along with Chinook salmon and silver salmon O. kisutch (Coho). As late as 1959, sockeye salmon were still called blueback salmon by R.R. French and R.J. Wahle in Biology of Chinook and Blueback Salmon and Steelhead in the Wenatchee River System. Angling authors have also mentioned bluebacks in their writings. 

While fishing near Gray’s Harbor in southwestern Washington, John Atherton wrote in The Fly and the Fish, “During the late summer and early fall, before the run of large steelheads began, we used to fish for what was locally called bluebacks”. He also reported he sent specimens of fish he caught that weighed from one to three pounds to Dr. David Starr Jordan at Stanford University for identification. Jordan reported that the fish were “small steelheads, similar to the half-pounders of Oregon”. 

Later reports…

Later, Trey Combs, in Steelhead Fly-fishing, suggested blueback was a name indiscriminately applied to several species of trout. Local anglers called the rainbow trout from Lake Crescent, Washington, bluebacks, or Beardslee trout. The fish was reported to live in deep water, were bluish-black along the upper sides with a whitish coloration underneath. However, this coloration is not uncommon for lake-dwelling rainbow trout throughout the West. In addition, some Oregon anglers and fishing guides call coastal cutthroat trout O. clarki clarki bluebacks or blueback trout. 

For many years, anglers called late entering winter steelhead from northern California rivers bluebacks. Tom Satterthwaite is a Fisheries Biologist with the Oregon Department of Fish and Wildlife. He suggested bluebacks might be a distinct subset of the winter steelhead run. Satterthwaite indicated most winter steelhead return on their first spawning run after 2 years and weigh from 6-10 pounds. Bluebacks return in February and March after just 10 months in saltwater. Consequently weighing much less, often two to six pounds. If some of the Nimbus Fish Hatchery juvenile steelhead released returned as blueblacks, they would be adipose fin marked. 

Unmarked steelhead

Unmarked steelhead or rainbow trout caught in the American River in springtime are most likely strays from the Sacramento River. As mentioned earlier, the Sacramento River historically supported a steelhead run that numbered in the several thousands. Today, dams have altered water quality and quantity. As a result, the Sacramento River downstream from the town of Redding supports a significant resident rainbow trout fishery. A few steelhead are observed in the river each year. The Coleman National Fish Hatchery continues to propagate a late summer/early fall run of Central Valley Steelhead. Similar to other California anadromous hatcheries, all juvenile fish released from the hatchery are adipose fin marked. 

In Conclusion

Studies have demonstrated the ability to migrate to the ocean is not completely lost in resident rainbow trout populations. A hatchery stocking program does not exist in the Sacramento River below Redding due to Fish and Game Commission policies. As such, it is likely some of the naturally produced juvenile resident trout eventually migrate to the ocean. These will return as steelhead. The American River has abundant flow and cool water temperatures in the spring months. Some of these returning naturally produced steelhead may enter the American River. American River spring steelhead are not as large as the winter steelhead and their numbers are highly variable. Nonetheless, easy access to the lower American River provides local anglers a unique fishing opportunity.

Assorted fly boxes for fishing the American River are available to purchase.
For suggested reading: Introducing the miracle of Smoltification of Anadromous Salmonids