Heading to GTNP and Yellowstone in July. For the YNP segment, I have 2 days booked at the Old Faithful Inn and 2 days at Lake Yellowstone. We will likely be having breakfast and dinners at the lodges, but how about lunches? I assume I'll be able to stock up on picnic items prior to entering the park, but how about while in the park? I think I read about one of the hotels having a sandwich shop, but not sure about other stores in the park.