REI Co-op Guide to National Parks is your comprehensive guide to hiking and site seeing in our National Parks.

• Currently packing complete trail data and hike descriptions for many of your favorite National Parks, including life-list destinations like Yellowstone, Yosemite, Grand Canyon, Zion, Grand Teton, Mount Rainier, Point Reyes, Rocky Mountain, Zion, Glacier, Acadia, Great Smoky, and more!
• Search for hikes using the map or a park's “best of” list curated through star rankings from the community.
• Never get lost again! See your live position on a terrain or satellite map and vertical profile
• No cell signal needed. The data is available offline, and your phone uses its built-in GPS to show your location.
• Plan the perfect trip for you, using our hike difficulty ratings, elevation profiles, star ratings, and informed insights on seasons, camping and lodging, guided tours, food and drink, and more.
• Traveling with kids? We have an expert-selected list of Family Friendly Hikes. Want to target the park’s most beautiful features? View our list of Gems.
• Other cool features: Create a to-do list, upload your photos, record a GPS track, or send your exact location to help in case of emergency.
• The app is completely free--our gift to you as part of the 2016 National Park Service's Centennial Celebration.

By using GPS, we can show your location on trails and vertical profiles. Continued use of GPS running in the background can dramatically decrease battery life.