Colorado's River Otters Are Making a Comeback—And They Need Your Help

Picture Colorado’s rivers teeming with otters—sleek, playful, impossible to ignore. That was the reality more than a century ago, before unregulated trapping and pollution wiped them out entirely. Now, after 50 years of dedicated reintroduction efforts by Colorado Parks and Wildlife (CPW), these charming creatures are returning to their native waterways, and the state is asking Coloradans to join the recovery mission.

The numbers tell a hopeful story. Where otters once seemed like a distant memory, sightings are now increasing—a tangible sign that decades of conservation work are actually paying off. But CPW knows that eyes on the ground matter. That’s why they’re enlisting citizen scientists through iNaturalist, the same platform that’s already proven its worth in uncovering new species, tracking invasive populations, and making discoveries that would otherwise slip past official surveys. Your smartphone, your keen eye, and five minutes can genuinely contribute to understanding where otters are thriving and where they still need protection.

It’s easy to dismiss this as a feel-good story about cute animals getting more attention than they deserve. And yes, charismatic wildlife does tend to hog the conservation spotlight. But there’s something deeper here: river otters are an indicator species. Their presence signals healthy waterways—clean water, abundant fish, functioning ecosystems. When otters come back, everything downstream benefits. That’s why CPW’s half-century commitment matters, and why your otter sighting—snapped and uploaded to iNaturalist—is worth more than just a nice photo.

Colorado’s river otter comeback is still fragile. Citizen science gives it staying power.