Friends Brian McKinney and Sam Vonderheide hoped to see a lot of wildlife on their 12-day hike to the top of Mount Whitney in California. But they never expected to spend the first night of the trip in a standoff with a mountain lion.

Mountain lions, or cougars, are large, powerful predators that usually ambush deer. They are secretive cats though, and tend to disappear long before hikers ever come close enough to see them. (Related: “Watch a Cougar Take Down a Deer in Rare Video”)

So when Vonderheide, a math teacher, said he thought he saw a mountain lion’s tail on the trail in front of him, McKinney figured he was mistaken.

“I didn’t believe him, but I turned