Haystack Mountain — Castle Hill, Maine This moderate hike covers 0.5 miles with an elevation gain of 183 feet, andis an out-and-back trail thattakes about 0.5–1 hour to complete. The short but rugged hike leads to a summit with 360-degree views of northern Maine, Mount Katahdin, and the wind mill farm at Mars Hill. The trail is steep and requires some rock scrambling near the summit. An informational kiosk at the trailhead provides information about the geological history of the mountain, including its history as a stratovolcano. The rocky trail requires closed-toe shoes, anddogs are welcome but must be on a leash.