It's the best when you can get them to walk off leash for hikes. I do a lot of remote hikes, that way I can leave my dog off leash. She's very well behaved, but I still put her on leash when we see other people/dogs. I never know how someone else's dog will react, and sometimes people are scared of dogs as well.

Carry lots of treats with you, and they'll hang around even when off leash. Just watch out for bears, they like treats too ;-)