S-130 Map and Compass 5 — Questions and Answers
Question 1: When the western United States has an eastern magnetic declination, which direction must you adjust a compass bearing to get a true bearing?
- Add the declination to the compass bearing
- Subtract the declination from the compass bearing (Correct answer)
- Multiply the bearing by the declination factor
- No adjustment is needed east of the Mississippi
Correct answer: Subtract the declination from the compass bearing
In areas of east declination (where magnetic north is east of true north), subtract the declination value from the compass bearing to obtain the true bearing.
Question 2: A firefighter estimates they are walking at roughly 3 mph. How long should it take them to travel 1.5 miles to a safety zone?
- 15 minutes
- 30 minutes (Correct answer)
- 45 minutes
- 60 minutes
Correct answer: 30 minutes
At 3 mph, traveling 1.5 miles takes 30 minutes (1.5 ÷ 3 = 0.5 hours = 30 minutes).
Question 3: What is the primary reason wildland firefighters carry a compass in addition to a GPS device?
- A compass shows current fire weather
- GPS units can fail due to dead batteries or signal loss, while a compass is always reliable (Correct answer)
- A compass is required by OSHA for all outdoor workers
- GPS cannot show terrain contours
Correct answer: GPS units can fail due to dead batteries or signal loss, while a compass is always reliable
A magnetic compass requires no batteries or satellite signal, making it a reliable backup navigation tool when GPS fails in remote terrain.
Question 4: On a topographic map, what terrain feature is indicated by contour lines that merge or nearly touch?
- A gentle slope
- A cliff or very steep terrain (Correct answer)
- A broad valley floor
- A ridgeline saddle
Correct answer: A cliff or very steep terrain
Contour lines that merge or appear to touch indicate a cliff or extremely steep slope — a critical hazard for firefighter escape route planning.
Question 5: Which of the following best describes a 'section' in the Public Land Survey System (PLSS)?
- A 6-mile by 6-mile square township subdivision
- A 1-mile by 1-mile unit of land containing approximately 640 acres (Correct answer)
- A quarter-mile grid square used in urban fire operations
- A county-level administrative boundary
Correct answer: A 1-mile by 1-mile unit of land containing approximately 640 acres
A PLSS section is a 1-mile × 1-mile square (640 acres), one of 36 sections that make up a township, commonly used to report fire locations in the western U.S.
Question 6: When using a map and compass to plan an escape route during a wildland fire, what terrain feature should a firefighter generally move TOWARD?
- Narrow canyons and drainages
- Ridgetops, saddles, or previously burned areas (Correct answer)
- Dense unburned fuel concentrations
- Areas immediately downwind of the fire
Correct answer: Ridgetops, saddles, or previously burned areas
Ridgetops, saddles, and burned areas provide defensible safety zones with reduced fuel loads and better visibility — standard LCES guidance.
Question 7: What does the RF (Representative Fraction) of 1:24,000 mean on a topographic map?
- 1 inch on the map equals 24,000 feet on the ground
- 1 unit on the map equals 24,000 of the same units on the ground (Correct answer)
- The map covers 24,000 square miles
- 24,000 contour lines appear on the map
Correct answer: 1 unit on the map equals 24,000 of the same units on the ground
A representative fraction of 1:24,000 means that 1 unit of measurement on the map equals 24,000 of the same units in reality (e.g., 1 cm = 24,000 cm = 240 m).
S-130 Map and Compass 5
When the western United States has an eastern magnetic declination, which direction must you adjust a compass bearing to get a true bearing?