For nearly three decades, Cal Poly Humboldt Wildlife Professor Jeff Black and citizen scientists have been quietly documenting the lives of one of the North Coast’s most charismatic residents: river otters. Now, marking the 27th and final year of this long-term research effort, Black is sharing new observations at the Arcata Marsh & Wildlife Sanctuary—a place where wastewater treatment, wildlife habitat, and public access intersect. Based on two years of intensive study, the latest findings, published in the Northwestern Naturalist, reveal just how deeply river otters rely on the marsh. Otters were present nearly every day, using the wetlands not only to hunt, but to raise pups, socialize, rest, and navigate a landscape shared with hundreds of daily visitors.