Dogs reacting in Anchorage County, Alaska

Me and a couple of friends had been bored, when I decided we should take a walk through the woods behind my house. I didn't think much of it, as me and my friend have done it many times before. There were four of us, and we set out at about 11 o'clock at night. It was rather dark, but there was light from the moon. The weather was rather cold, as we did this in the winter. The area we walked on was game trails (trails that moose walk on) as well as trails used for mushers, runners, cross country skiiers, and that sort. We had walked about 2 miles from my house to another entrance where most people enter. On the way we had talked about unexplainable events or things such as bigfoot, and UFOs. When we reached the bridge where most people come in, one friend had smoked a cigarette. We then saw a light and decided to go on. On the way back, we heard wild dogs barking wildly, and decided to pick up the speed. It eventually became a sprint, whereafter we walked. When we walked, we continued talking about it. It was then I had realized, some thing had been following us, as well as testing us, or even harassing us. It was much earlier, I just didnt think about it. I had thought it was my friend Warren, who is sometimes clumsy. I had thought it was him who had made noises such as slipping, but it was really something throwing stuff at us. I had realized this about half way back. I asked if Warren kept slipping, when he told me it wasn't, and he thought I could have been pulling a prank. We stopped for a minute to listen when I told the others something strange was going on. We stopped, and shone a flashlight around, hearing noises such as steps, and branches moving and breaking. The leader had thought I had been playing a joke when I told him seriously, I wasn't. He decided to walk behind with me, when something threw snowballs, and nearly hit us on many occasions. It was then he realized that this was no joke, and we picked up a light jog, for most of the way. When we were almost out of the woods, we had again heard dogs, and maybe 20 ft away, the branches breaking, and again, something throwing stuff at us. By the time we left, it was about 3-3:30 in the morning. I did not go directly to my house because I didn't know if it was still following us. I know this was not a prank because the snow is more then 5 ft deep in the woods, and someone would have a extremely hard time to play a prank like that.