The community science project will help understand previous reintroduction success and any limitations to it going forward.

DENVER — Colorado Parks and Wildlife (CPW) is asking the public to help document river otters through a new community science project.

The science project, the iNaturalist Otter Y.E.A.R. project, is part of CPW’s 2026 Otter Y.E.A.R. (Yearlong Engagement and Assessment of River Otters.)

Colorado residents and visitors can submit photos and locations of river otters or signs of their presence, CPW said. 

Along with public participation, CPW staff and partner organizations will conduct surveys throughout 2026, which includes scheduled efforts on the Yampa, Green, Colorado, and Gunnison rivers. Data collected this year will inform future conservation work, including potential reintroduction efforts into suitable habitats that remain unoccupied, CPW said.

This project marks the 50th anniversary of the river otter reintroduction in Colorado, CPW said in a media release. Otters once occupied the major rivers of the state, but were wiped out by the early 1900s due to the absence of any rules governing wildlife and water pollution. The Colorado Division of Wildlife reintroduced 120 river otters between 1976 and 1991 at Cheeseman Reservoir, the Gunnison River, the Piedra River, the stretch of the upper Colorado River that runs through Rocky Mountain National Park and the Dolores River, according to CPW’s website.

“Coloradans who enjoy river otters today have that opportunity because of the vision and dedicated work 50 years ago by Division of Wildlife employees and several graduate students, along with the Pittman-Robertson dollars used to fund the effort,” River Otter Program Manager Bob Inman said. “This year’s survey will help us understand the extent of reintroduction success and any limitations to it.” 


How to participate

If you want to participate and submit your river otter photos, here’s how you can:

If you think you’ve found a river otter and are unsure about it, CPW has a guide to distinguish otters from other swimming mammals like beavers, muskrats, and minks on the Otter Y.E.A.R. website since all of them have similar characteristics and live in the same habitat.

Participants in the project will have the opportunity to see their submissions featured in monthly “Otter Photo of the Month” highlights on CPW’s social medias. Also, by contributing, people will play a direct role in wildlife conservation and help CPW build a clearer picture of where river otters are across Colorado.