Park Rules
Every national or state park will have different rules and regulations for their parks and those enjoying the hiking trails. These should be posted at the entrance to the park, but you should contact the park first to obtain a copy of the rules and regulations prior to setting off on your hike. Such rules are in place to keep you and your pets safe. Even with the rules in hand, dog owners should acquire the following:
Always keep your eye on your dog. Mischief can happen quickly.
Never leave your dog unattended.
Always fill in any holes your dog digs.
Always use a leash. (Each park has different regulations as to the length of the leash.)
Dog owners must obtain permits for their dogs (where necessary).
All dogs should be up to date on their vaccinations.
Always clean up after dogs.
Aggressive dogs are not allowed on any public hiking trails or open beach areas.
U.S. Parks
Now that you are armed with all this knowledge and are ready to hit the trails with your canine companion, where do you go? Lucky for us, there are many parks across the United States that allow dogs. To help you find them, here are a few "dog friendly" directory listings on hiking trails.
DogFriendly.com - http://www.dogfriendly.com/server/travel/guides/park/park.shtml
Hike with Your Dog - http://www.hikewithyourdog.com
Pet Friendly Travel - http://www.petfriendlytravel.com/?page=state_parks
Hiking Resources
There are also many offline resources that can help you become more knowledgeable about hiking with your dog. Some of these resources include books, such as:
A Guide to Backpacking With Your Dog by Charlene G. Labelle
First Aid for Dogs: What to do When Emergencies Happen by Bruce Fogle
Ruffing It: The Complete Guide to Camping With Dogs by Mardi Richmond
The Canine Hiker's Bible by Doug Gelbert
The Pet Travel and Fun Authority of Best-of-State Places to Play, Stay & Have Fun Along the Way: 35,000+ Accommodations, Pet Sitters, Kennels, Dog Parks ... Tons-of-Pet Fun & More Guide! 12th Edition by M. E. Nelson
References:
Copeland, D. (2005). Backpacking Doggy Style: Basics for Hiking with Dogs.
Hiking with Dogs. (2007). Appalachian Trail Conservatory.