Yellowstone River Otter
Playful on ice-free rivers — a joyful sighting.
Overview
North American river otters (Lontra canadensis) are aquatic mustelids that live along Yellowstone's rivers and lakes. They're social and playful — groups slide, chase, and wrestle, and their droppings (scat) and slide marks on snow banks betray their presence.
Look where rivers stay ice-free in winter — open leads of water along the Yellowstone, Lamar, and Madison rivers.
Where to find them
- Yellowstone River (Hayden): Open leads in winter.
- Lamar River: Year-round otter habitat.
- Madison River: Reliable in winter.
When to look
Year-round, daytime. Winter can be excellent where water stays open.
⚠️Stay at least 25 yd away
Frequently asked questions
Where can I see river otters in Yellowstone?+
Along rivers and lakes that stay open in winter — the Yellowstone (Hayden Valley), Lamar, and Madison rivers. Look for slide marks on snow banks and groups of animals surfacing in open water.
Are river otters the same as sea otters?+
No — river otters are smaller, freshwater, and much more agile on land (sea otters barely come ashore). River otters are the ones in Yellowstone.
Sources & data notes
- River Otter data is drawn from official NPS, USGS, and NOAA sources catalogued in our source registry. Observer-submitted sightings are not published on this public guide.
- River Otter is documented via NPS reference pages; no dedicated population time-series is in the public dataset.
- NPS Yellowstone mammals overview — National Park Service (Official mammal checklist/context page with current park-level population notes; not point data.)
- NPS Yellowstone wildlife overview — National Park Service (Official wildlife viewing and habitat context; not observation records.)
Spotted something off, or want a deeper dive? Every claim above links to its original source — look for the ↗ markers and the Sources section.