Topographic Maps: Your Foundation
A topographic (topo) map shows terrain in three dimensions using contour lines — lines connecting points of equal elevation. Understanding contour lines lets you "see" mountains, valleys, ridges, and cliffs before you reach them.
Reading Contour Lines
- Contour interval: The elevation change between adjacent contour lines (typically 40 ft on USGS 7.5-minute quads)
- Closely spaced lines = steep terrain; widely spaced = gentle slopes
- V-shapes pointing uphill = valleys/drainages; V-shapes pointing downhill = ridges
- Closed circles = summits or depressions
Where to Get Maps
- USGS Topo Maps (free): Free 7.5-minute quad maps at nationalmap.gov or via the Avenza Maps app
- Caltopo: Best online topo mapping platform for trip planning and custom map printing. Free and paid tiers.
- National Geographic Trails Illustrated: Waterproof printed maps for specific trail areas — ideal for National Parks
- Gaia GPS: Best mobile app for offline topo maps. Download before you leave cell service.
Compass Basics: Never Rely on a Single Navigation Tool
A compass does one thing: points to magnetic north. Combined with a topo map, it lets you determine your exact position, navigate to a destination, and follow a bearing through terrain with no trail.
Essential Compass Skills
- Declination adjustment: Magnetic north ≠ true north. In the western US, declination is 10–15°E. Adjust your compass or the difference will send you off-route. Most quality baseplate compasses have an adjustable declination.
- Taking a bearing: Point compass at a landmark, rotate bezel until magnetic needle aligns with orienting arrow. Read bearing at index mark.
- Following a bearing: Hold compass level, rotate body until needle aligns with N, walk toward a landmark in the direction of travel arrow.
- Triangulation: Take bearings to two known landmarks, draw lines on map — your position is the intersection.
GPS Devices vs Phone Apps
| Factor | Dedicated GPS (Garmin) | Phone + App (Gaia/AllTrails) |
|---|---|---|
| Battery Life | 15–25 hours | 4–8 hours (can extend with battery pack) |
| Durability | Waterproof, shock-resistant | Varies; most not waterproof without case |
| Map Quality | Good (some models excellent) | Excellent (Caltopo, Gaia layers) |
| Cost | $350–600 | $0–40/year app subscription |
| Signal Acquisition | Faster, multi-constellation (GPS+GLONASS) | Usually adequate; slower in deep canyon |
| Cold Weather | Works to -4°F (-20°C) | Battery dies faster in cold |
Recommendation: For most backpackers on maintained trails, a phone with Gaia GPS (offline maps downloaded) is sufficient and far cheaper. Add a 10,000mAh battery pack for multi-day trips. Upgrade to a dedicated GPS for off-trail travel, international expeditions, or areas with extreme cold or rain.
Emergency Communication: The Most Important Gear Decision
In a backcountry emergency, your phone almost certainly has no signal. A satellite communicator is the only device that can summon help from anywhere on Earth. This is not optional safety gear for solo backpackers or remote routes — it's essential.
Satellite Communicator Options
- Garmin inReach Mini 2: Two-way messaging, SOS via GEOS, GPS tracking, weather forecasts. 14-day battery. $350 + $14.95/month subscription.
- SPOT Gen4: One-way messaging (no two-way text), SOS via GEOS. Simpler and cheaper. $150 + $12/month.
- Zoleo: Two-way global messaging, SOS, check-in messages. Best app interface. $200 + $20/month.
See our full comparison in the Satellite Communicator Buyer's Guide.
Trip Planning & Leave a Trip Plan
The most important safety act costs zero dollars and zero ounces: leave a detailed trip plan with a responsible person before every backcountry trip.
What Your Trip Plan Should Include
- Trailhead location (GPS coordinates + access road name)
- Planned route — not just "John Muir Trail" but specific campsites each night
- Expected return date and time
- Vehicle description and license plate at trailhead
- Names and contact info of all trip members
- When to call Search and Rescue (typically: 24–48 hours past expected return)
- Your satellite communicator model and device IMEI number
Sources & Further Reading
- USGS. "National Map Viewer and Download." nationalmap.gov
- National Outdoor Leadership School (NOLS). "Wilderness Navigation." nols.edu
- Search and Rescue teams, NASAR. "Trip Planning Best Practices." nasar.org
- Caltopo. "Backcountry Navigation Guide." caltopo.com
- REI Co-op. "How to Use a Compass." rei.com/learn
