User Mary Greeley posted the video on her YouTube channel at the end of December and it has garnered about 25,000 views since then.
Yellowstone National Park Spokesperson Al Nash says such sightings occur from time to time.
"Bigfoot sightings are not frequent, but it happens. People say a lot of crazy things about Yellowstone all the time and Bigfoot is just one of them."
The Bigfoot Field Researchers Organizations reports Montana has a total of 43 reported Bigfoot sightings since it was founded in 1995.
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