Majority of the red salmon went up the middle of the Klutina River and tended to weigh a pound or less.
Observation: Sockeye/Red salmon (Oncorhynchus nerka) have in my history traveled along the banks of the Klutina River toward spawning grounds. The bigger Chinook/King (Oncorhynchus tshawytscha) salmon took the faster water in the middle of the river, except when resting in pools. Last summer, the majority of the red salmon went up the middle and tended to be up to a pound or smaller. In the years I worked for NPS, we gave the Klutina River a class III-IV white water conditions with flows of 25 knots. I live on this river.
Consult: This post was forward to Ted Meyers (ADF&G), he writes, "If salmon have the opportunity, most species would prefer to migrate upstream in the middle of the river to avoid predators. However, if the current is too swift some species opt for the lesser water flows along the edges. These past two summers in Alaska river volumes overall have been lower so perhaps the slower current has permitted these sockeye to pass through the center of the river rather than the edges. Only a guess." Ted (DFG) 2016-02-23
LEO says: Alaska Department of Fish & Game - Upper Copper-Upper Susitna Management Area: The Klutina River flows east from Klutina Lake to the Copper River at Copper Center. The river is a glacial fed system with class III – IV whitewater and has excellent fishing for sockeye and king salmon, Dolly Varden and Arctic grayling as well as some rainbow trout. King salmon are available in July and early August, sockeye salmon from June through August, and all other fish are available from June through October. The lower river can be accessed for fishing at the old Richardson Highway Bridge, and also off the public access portions of the Klutina Lake Road. The river also makes for a half to 2 day float trip, depending on the put-in point, with mostly Class III conditions, and a few Class IV water sections. Additional material could be found at the American Whitewater (AW) website.
Resource:
Alaska Department of Fish & Game, Range and Habitat - Sockeye Salmon (Oncorhynchus nerka), for the time being, salmon habitat in Alaska remains mostly pristine. There are hundreds of stocks of sockeye salmon throughout the state of Alaska and their population trends are diverse: Some stocks are in decline while others are at equilibrium or increasing. Potential future threats include habitat loss, habitat degradation, climate change, and over fishing.
Alaska Department of Fish & Game, Range and Habitat - Chinook Salmon (Oncorhynchus tshawytscha), Fresh water streams and estuaries provide important habitat for spawning chinook, and they also serve as nursery grounds for developing eggs, fry, and juveniles. In North America, Chinook salmon range from the Monterey Bay area of California to the Chukchi Sea area of Alaska. On the Asian coast, Chinook salmon occur from the Anadyr River area of Siberia southward to Hokkaido, Japan. In Alaska, they are abundant from the southeastern panhandle to the Yukon River. Major populations return to the Yukon, Kuskokwim, Nushagak, Susitna, Kenai, Copper, Alsek, Taku, and Stikine rivers. Important runs also occur in many smaller streams.