Why, yes, I did make a map to show the route Darcy and Elizabeth travel. In a journey story, the setting is particularly important, and when a setting is as well-known as the Appalachian Trail, you had better get your details right!
I used a number of resources to flesh out when and where certain scenes would take place, including the Appalachian Trail Conservancy’s Interactive Map, the Appalachian Trail Distance Calculator, and Google Maps’ cool geotagged image service Panoramio. My outline was organized by day and mile, and I wound up keeping those notations as chapter headings to show the overall progress of our backpackers. Over the course of the hike, the mileage climbs as they get further away from New York City, and the days count down to Darcy’s birthday deadline.
But back to the map, the pins mark real landmarks as well as the approximate locations of fake places featured in the book. You can zoom in and explore as much as you like, but be warned: clicking on the pins, especially further to the south and west, may reveal spoilers.