Video footage of a strange snake-like creature covered in ice has recently gone viral on social media.
The peculiar spectacle was spotted by Craig McCaa from the Bureau of Land Management (BLM) while he was out taking pictures of the Chena River to help chart seasonal landscape changes.
"I don't know what I would have done if I had come by in a canoe or something," he said. "But looking from it above on the University Avenue bridge I didn't feel too threatened."
The 'creature', which was around 15ft long, remained semi-submerged in the freezing river throughout the encounter and appeared to have a surprising amount of ice on its back.
McCaa uploaded the footage on to the bureau's Facebook page on Tuesday and it went viral soon afterwards, clocking up tens of thousands of views within a short space of time.
"I initially thought, and several people thought, it could be some rope that snagged on the bottom of the river with chunks of ice," he said.
"Other people have mentioned everything from sea monster to giant sturgeon."