If you have a local backpacking shop, go there. Ask the staff (and even other customers that seem to know the staff) where they like to go. Also, most local shops have a book section; it usually isn't very large, but it contains mostly hiking guides, often with a heavy local tilt.

REI is usually also a good source. However, their book section tends to be a little more generic and a little less local.

Finally, go to the local bookstore (including Barnes and Noble or Borders.) Look two places: Local Interest and Sports (Outdoor Sports, Camping, Backpacking, Mountaineering.) Occasionally you can find something in the Travel section, too.