Officials say a beaver dam helped prevent an oil spill from getting to far into the Arkansas River near Florence.
Environmental Protection Agency spokesman Ted Linnert says a pool of oil 50-feet long, 20-feet wide and as much as 18-inches deep was stopped behind the structure of sticks and logs on Oak Creek.
Some beavers and muskrats were killed.
The oil spill was estimated at up to 200 gallons. It leaked from a tank owned by Fremont Paving and Redi-Mix of Canon City.