We stumbled upon this market when we were in the area to visit Lake Placid. We went in for tea and coffee and discovered they had gluten free brownies and blondies (individually packaged and wrapped -- from a company called Freed Goods Co in The Bronx, NY) in their refrigerated case right up front. When I looked around, I noticed TONS of gluten free products in the market, which is a one-room store stocked well with high-quality grocery items. They had many items on the shelves that were gluten free, like crackers, pasta, cookies, soups, salsas, pasta sauce, and all the basic necessities. They were all the good brands that we buy back home, including gluten free Xochitl corn chips (also non-GMO). They had freezer and refrigerated cases, too, which had many gluten free items: gluten free waffles, gluten free frozen meals, etc. They also sell fresh eggs at the store, plus expresso based drinks like lattes and capuccinos. About the only thing I didn't see here were meats and fresh fruits and veggies. Just about anything else you'd need for a local stay can be purchased here. The ladies working there were so friendly, too, and they said they also make some gluten free baked goods. We bought the pre-packaged brownies and blondies, which were expensive but very good.
The ADK Cafe, right around the corner at 2837 NY-73 Scenic in Keene, which is under the same ownership, apparently also has gluten free choices on their menu. Their website is http://www.theadkcafe.com