Route Planning with Topographic Maps

The Planning Process

Good route planning happens in four stages: terrain analysis, route selection, waypoint marking, and contingency planning. Skip any stage and you miss information that matters when you're in the field.

Stage 1: Terrain Analysis

Before drawing any line on the map, understand what's between your start and end points.

Read the contours:

• Identify all high-relief features: ridges, cliff bands (very close contour lines), peaks
• Identify all low-relief features: valleys, drainages, saddles, benches
• Find the major obstacles: steep slopes, cliff bands (where contour lines touch or nearly touch), swamps (shown as blue or green hatching), rivers and streams

Mark the obstacles: Draw a light circle around or through any terrain feature that will stop or significantly slow your travel:

• Cliff bands
• Major stream crossings without bridges
• Dense vegetation (shown as green shading on most maps)
• Wet areas (blue/green hatching)
• Actively steep terrain (closely-spaced contours more than a few hundred feet vertical)

Identify the natural routes: Ridges and valleys already solve the route-finding problem for you. A ridgeline is a natural highway — no brush, good visibility, reliable footing in most terrain. A valley floor follows water (toward lower terrain) and avoids most steep terrain. Look for natural routes between your obstacles before forcing a direct line.

Stage 2: Route Selection

With terrain obstacles identified and natural routes visible, select your specific route.

The decision criteria:

1. Does the route avoid the marked obstacles, or cross them at their easiest points?
2. Does the route use terrain features (ridges, benches, valley floors) that are naturally passable?
3. Does it have reliable waypoints — terrain features you'll recognize and can confirm your position at?
4. Does it minimize total elevation change (unnecessary climbing is expensive in time and energy)?
5. Is there a way to abort and reverse if conditions change?

Draw the route: Mark your start, end, and each major waypoint. Connect them with a light pencil line. This line doesn't follow roads — it follows terrain.

Check the route segments: For each segment between waypoints, ask: What bearing am I traveling? What terrain will I cross? What will I see when I arrive at the waypoint?

Stage 3: Waypoint Selection

Waypoints are identifiable terrain features along your route that confirm your position when you reach them. Good waypoints are unmistakable and require no interpretation.

Excellent waypoints:

• The top of a named peak
• A saddle between two distinctive hills
• The confluence of two named streams
• The intersection of a trail and a ridgeline
• A lake or pond
• A distinctive rock formation or terrain break

Poor waypoints:

• "The big tree" (which big tree?)
• "The bend in the trail" (there are many)
• A minor drainage with no distinctive features
• Any feature described by "approximately" or "about"

Mark waypoints with their coordinates or a description precise enough that you'll recognize the feature in the field.

Stage 4: Bearing and Distance Calculations

For each route segment:

Bearing: Measure with the compass or protractor between each waypoint pair. Adjust for declination. Record it.

Distance: Lay a thin string along the route on the map, connecting each waypoint. Mark the string at each waypoint. Transfer the total string length to the bar scale in the map margin.

Elevation change: At each waypoint, read its elevation from the labeled contour lines. Calculate gain and loss between waypoints.

Time estimate (Naismith's Rule):

• Add 1 hour per 3 miles of horizontal distance
• Add 1 hour per 2,000 feet of elevation gain
• Add 30 minutes per 1,000 feet of steep descent (over about 1,500 feet)
• Off-trail travel: multiply total time by 1.5-2x

Build in a buffer of 20-30% for unforeseen conditions (weather, injury, navigation errors, terrain that looks passable on the map but isn't).

Recording the Route

Before leaving, record your route on a single sheet:

| Leg | From | To | Bearing | Distance | Est. Time | Notes | |---|---|---|---|---|---|---| | 1 | Trailhead | Upper saddle | 035° | 2.2 mi | 1.5 hrs | 800ft gain | | 2 | Upper saddle | Summit | 015° | 0.8 mi | 0.75 hrs | 600ft gain | | 3 | Summit | Camp | 280° | 1.5 mi | 1 hr | 1,200ft descent |

Leave a copy of this sheet with someone who will know to call for help if you don't check in by a specific time.

Contingency Planning

For every route, identify:

• The last safe bail-out point before the most difficult terrain
• A turn-around time (if you haven't reached X waypoint by Y time, turn around)
• An emergency shelter option if conditions prevent return

The turn-around time is the most commonly skipped element of route planning. Write it on the route sheet. A specific time ("if not at the saddle by 2 PM, turn around") removes the in-the-moment pressure to push on when you shouldn't.