Assuming I brought in their food and wasn't growing it on my land, how much space would about a half-dozen sheep need?
Also, my land is heavily wooded and is going to be thinned a bit and cleared in a few spots. Do sheep do well in the mountains?
I don't know but I just came across a book you might enjoy-- The Dogs of Bedlam Farm-- the author, Jon Katz,bought an old hilly farm so he could raise sheep and working border collies. I just started the part where the sheep are delivered and the neighbors are telling him how nice it is to see sheep up on the hill again so that suggests to me that hilly terrain is fine for sheep. Might be good info in there or ideas for resources.
I don't have personal experience with sheep, but think about where sheep live in Europe: I think of Scotland and Ireland and the Pyrenees. They do very well in hilly areas. I remember spending about an hour with my mom, standing at the bottom of a huge hill in scotland, watching border collies drive a flock of sheep straight down the edge of this small mountain. The farmers drove the dogs up to the top of the hill, then got in their car and drove down the windy road to wait at the bottom while the dogs took the sheep straight down the very steep side. It was amazing.