A hiker encountered a big bull moose while trekking to an alpine lake in Clear Creek County, Colorado. The individual, whose identity has not been released, was already quite close to the bull upon noticing it. The person watched the bull for a couple of seconds, pulled out a phone, and started recording a video. At first, the bull appears to be calmly munching on some willows, before it suddenly turns its head towards the hiker and charges.

According to Colorado Parks and Wildlife (CPW) public information officer Jason Clay, “the person was able to dive behind a tree, and the moose hit that tree. He then walked away in another direction away from the moose without any injuries.”

Moose attacks are rare but have been increasing in frequency in Colorado. Bull moose are known to be territorial and can be especially aggressive during the fall rut. Public wildlife officials are hoping to use this close encounter to educate people about what to do in the case of a surprise moose encounter. CPW Northeast Region wrote in a Twitter post: “This video is an example of being too close to a bull moose and how quickly they can decide to charge you.”

The best way to avoid moose attacks is to keep your distance, though it’s possible to unintentionally stumble upon a moose without noticing it. CPW officials note that a moose “squaring up” to you is a warning sign that you’re too close. If you get into this kind of situation, back away slowly while monitoring the moose’s behavior. Other signs of aggression include laid-back ears, raised neck hairs, and licking of the snout. If you’re in the unfortunate situation where a moose charges, run as fast as you can behind a tree, car, boulder, or anything large enough to get in the way of the moose.

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Moose are found across much of North America, from the northern regions of the Lower 48 up through Canada and Alaska. Moose are the largest and heaviest species in the deer family. Mature bulls can reach weights of up to 1,500 pounds, stand six feet tall, and wield paddles over 80 inches wide.