We are going to hike Mt. Washington with our 70lb schnauzer.
He often goes on long walks, he runs with me (up to 5 miles) and already completed few shorter hikes on and around NY sections of the AT.
Thanks for reaching out!
Sounds like a great trip! While I've never hiked Mt. Washington, I have traveled pretty extensively in the backcountry with my dog, Hadley (a ~75lb Alaskan Husky), and there are some considerations with dogs on the trail that apply regardless of which trail you're on. Additionally, we encourage you to check out this Expert Advice article, Hiking or Backpacking with Your Dog.
The most important thing is that you know your dog the best and are in the position of knowing the limits of their abilities. You want to keep a close eye on them when you're on the trail and look for any abnormal behaviors. Every time we take a break on the trail I check Hadley's paws for hot spots and her nose and tongue to make sure they're moist and cool. A trip in the backcountry with your dog can be an amazing experience, hopefully this helps!
I have hiked up Mt Washington (tuckerman’s ravine), the only thing I have to say is… please pick up after your dog and don’t leave the bag on the side of the trail like I just witnessed in bridger wilderness Wyoming…unbelievable
good luck and have fun!