Range: Historic range of the northern river otter extended from Alaska and Canada, southward, throughout most of the United States. They were found in many of the river basins of western and northern Colorado, including along the Arkansas River in Pueblo County. Trapping seriously reduced their numbers, but new laws now protect otters and wetlands, and their numbers are increasing.
Habitat: Riparian (river) habitats from shrublands to subalpine forests, providing good quality water with constant flow and ice-free areas
Conservation status: Least concern
Were extirpated (killed to extinction) in Colorado, but are making a comeback.
Reasons for extirpation:
• Their pelts were in demand for hats and coats until the 1930s,
• Killed by bounty hunters because they were believed to be opportunistic predators of game fish and waterfowl. Research has since shown that the river otter isn’t the consumer of game fish it was once thought to be.
• Around the 1950s, river otters encountered new problems—pesticides, heavy metals, and toxic waste. Since these animals are at the top of the food chain, any prey eaten that contains contaminants is concentrated in otter body tissues, often causing death.
• In 1976, Colorado became the first state to begin restoration of this species and populations were established in several drainages. Although relatively clean water is a requirement, otters are a pretty resilient species. They are highly adaptable possessing many survival traits.