I got chased by a bear after accidentally sneaking up on a mother and cub mountain biking in Aspen back in 1997. I had just finished climbing up Red Mountain to do the Sunnyside trail and I made some noise splashing through a puddle which apparently startled the bears. I heard snapping branches and stopped riding to look around because I thought it was some other mountain bikers. What I saw was a bear coming towards me in a full gallop with a bear cub scrambling up a pine tree behind it. Fortunately it was about 50 yards away so I turned around and flew down much of the hill I'd just finished climbing. I ended up riding to Laredo instead and didn't see another person for about two hours, but I was freaked out for the rest of the ride.