It's been so long since I've actually seen this film, but I'll try to put together all that I remember about the film...
-I recall a bus full of people, I believe it was a school bus, breaking down in the middle of the woods.
-Everyone seems to be stalked by a creature of some kind. I actually remember one scene in which the passengers of the bus get onto a raft and go down river, and then there is a shot of the creature climbing slowly up a rock, watching them.
-There is one scene in a cabin in the middle of the woods that has a dead body or skeleton in the cabinet. For some reason, I recall it possibly being a dog.
Seems pretty ambiguous, but it's worth a try.
A film which comes to mind which it could possibly be is The Final Terror (1983 release, though made in 1981).
http://www.imdb.com/title/tt0082379/
http://movies2.nytimes.com/gst/movies/movie.html?v_id=17304
You know, Final Terror sounds about right. In fact, I remember seeing that amongst my parents VHS collection, so I may have to watch it to see if that was it. Thanks, I'll report back on the matter after I've seen the film!