Hatchet had a sequel or two... I read "The River" which was what followed it when I was maybe 10-11 - pretty good book. there's another one called "the island" maybe - I have it, but haven't read it (just saw it and picked it up - I think its in storage).
Yeah, there is a Gary Paulsen book called The Island, but it's not a sequel, it's a whole different book. The one I got for Evolute (Brian's Winter) is kinda like a what if Hatchet sequel about if he didn't get out before winter, and what would have happened if he had to survive the winter.