Taking off impossibly fast in Anchorage County, Alaska

I and two of my friends were bored one night so we decided to do a little snowmachining. Though it was illegal to snowmachine in Anchorage, there were some good trails to ride on a little north of my house. We took off at probably 11 pm, rode up the road about a quarter mile, and cut off on the trails. It had snowed about 10 inches a few days before so there was fresh snow, with no tracks. I was leading the way for about a half hour, then we stopped and talked for a little bit. We took off again and kept cruising on some sort of game trail that led to an opening in the woods. I rode off into the opening with my friends following about fifty yards behind me. I came over this little mound and saw strange tracks leading to this spot in the snow where it looked like something had pushed aside some snow and layed down. I figured it was just a moose or something. But I followed the tracks over the next small hill and as I came down the far side my headlight pointed right on the back of a bigfoot. It was only about 10 to 12 feet in front of me. It was running in the opposite direction. I slammed on the brakes because I was scared out of my mind. It continued to run away, jumped over a dead log covered in snow and disappeared into a group of trees and into the darkness. I was so surprised and scared I quickly turned around and rode back toward my friends. I met them back by the first mound and said "We need to get out of here," and rode back towards my house. When I told them about it back near my house, they laughed and told me it was probably a bear or someone in the woods. But I was 100% positive that is was not a bear or anything else. The way it was running through the deep snow made me sure that it wasn't anything human. For a long time I was made fun of and everyone told me I was crazy so I didn't like talking about it.