Human impacts have led to a dramatic decline of salmon and steelhead populations in the Eel River system . Large-scale commercial fishing began in the 1850s , with multiple canneries on the Eel River operating into the early to mid 1900s . Between 1857 and 1921 , canning operations took an estimated 93,000 fish per year , with a peak of 600,000 fish in 1877 . By the 1890s , fish populations had already recorded a precipitous decline . Logging and grazing , which expose formerly forested land as bare ground , have had even greater impact on the populations of these fish . Due to the mountainous terrain and heavy precipitation in the Eel River watershed , erosion rates are particularly high . Much of the anadromous fish spawning habitat in the river system was covered by sediment or blocked by debris jams . Record flooding in 1955 and 1964 , which destroyed or damaged large amounts of habitat along the Eel and its tributaries , was generally regarded as the final blow . After the Christmas flood of 1964 , chinook salmon populations plunged to less than 10,000 per year
Christmas flood of 1964
Christmas flood of 1964
Eel River (California)