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PMS 437

Mapping: Map and Field Measurements

  1. Map Scale & Map Distance
  2. Slope Estimation
  3. Unit Conversions
  4. Average Latitude for Each State
  5. Declination

Map Scale & Map Distance

The map scale is printed in the map legend. It is given as a ratio of inches on the map corresponding to inches, feet, or miles on the ground. For example, a map scale indicating a ratio of 1: 24,000 (in/in), means that for every 1 inch on the map, 24,000 inches have been covered on the ground. Ground distances on maps are usually given in feet or miles.

ScaleRep. fractionMap (in/mi)Map (in/ch)Feet per map inch
1:253,440253.440.250.003121120
1:126,720126.720.500.006310560
1:63,36063.3610.01255280
1:62,50062.501.010.01275188
1:31,68031.6820.0252640
1:24,000242.640.0332000
1:21,12021.1230.03751760
1:15,84015.8440.051320
1:7,9207.9280.1660

Firefighter Math Map Scale; Firefighter Math Spread/Map Distance

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Slope Estimation

Slope (Degrees)Slope (Percent)
10°17.6%
20°36.4%
30°57.7%
40°83.9%
45°100%
50°119.2%
60°173.2%
70°274.7%
80°567.1%
90°∞

Standard LANDFIRE slope themes are represented in units of degrees (°). Many locally produced landscapes over the year’s stored slopes in percent (%). It is much easier to estimate slope in percent, estimating the elevation change and the horizontal distance and calculating the ratio. BehavePlus, and BEHAVE tools before that, default to slope input in percent.

Firefighter Math Slope Percent and Slope Angle

To convert from slope in degrees (°) to slope in percent (%), a scientific calculator is needed.

  1. Enter the slope in degrees.
  2. Press the Tangent button.
  3. Multiply the result by 100 to get slope in percent.

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Unit Conversions

Online and downloadable apps are available from Apple (OSX & IOS), Google Play (Android), and MS Windows for making unit conversions for distance, temperature, area, volume, weight, time, energy and other items.

Metric UnitMultiply byEnglish UnitMultiply byMetric Unit
Meters/min3.28084Ft/min0.3048Meters/min
Meters/min2.982582Ch/hr0.33528Meters/min
Meters/min0.03728Miles/hr26.8224Meters/min
Kg/m34.460897Tons/ac0.22417Kg/m3
Kg/m30.062lb/ft316.129Kg/m3
Tonnes/ha0.44609Tons/ac2.2417Tonnes/ha
Kw/m0.28909BTU/ft/sec3.4592Kw/m
Meters0.049709Chains20.117Meters
Meters0.3048Feet3.28084Meters
Millimeters0.0393701Inches25.4Millimeters
kilometers0.62137miles1.6093kilometers
hectares2.4711acres0.40469hectares

Firefighter Math Conversions reference provides several tables and conversion factors for the user.

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Average Latitude for Each State

StateAverage Latitude
Alabama33
Alaska65
Arizona35
Arkansas35
California38
Colorado39
Connecticut41
Delaware39
Florida28
Georgia33
Hawaii21
Idaho45
Illinois40
Indiana40
Iowa42
Kansas39
Kentucky37
Louisiana31
Maine45
Maryland39
Massachusetts42
Michigan43
Minnesota46
Mississippi32
Missouri39
Montana47
Nebraska41
Nevada39
New Hampshire44
New Jersey40
New Mexico34
New York43
North Carolina35
North Dakota47
Ohio40
Oklahoma35
Oregon44
Pennsylvania41
Rhode Island41
South Carolina34
South Dakota44
Tennessee36
Texas32
Utah39
Vermont44
Virginia37
Washington47
West Virginia38
Wisconsin44
Wyoming43

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Declination

Global Reference

Calculator

US/UK World Magnetic Model - Epoch 2015.0 Main Field Declination (D)

(East Declination in Red, West in Blue; subtract from true compass reading)

Recent map of magnetic declination for field navigation.

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NWCG Latest Announcements

NEW! S-212, Intermediate Faller (Online) Course Available Now 

Date:  April 23, 2026
Questions? 
Please contact: Hazard Tree and Tree Felling Subcommittee

NWCG is pleased to announce that the new S‑212, Intermediate Faller (Online), course is now available on the Wildland Fire Learning Portal (WFLP). This second course in the series provides students with the knowledge and skills required to perform the duties of an Intermediate Faller (FAL2), as described in the FAL2 Incident Position Description. This course is intended for individuals seeking to advance from Basic Faller (FAL3) to FAL2.

S‑212, Intermediate Faller is a fully online, self‑paced training program consisting of 13 units. Learners will engage with interactive, scenario‑based content designed to progressively build foundational skills and knowledge essential for the FAL2 role.

Students must be qualified as a Basic Faller (FAL3) prior to enrolling in S‑212, Intermediate Faller course.

Any changes to qualification pathways will take effect with the next update of the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1, scheduled for January 2027.

References:

S-212 Intermediate Faller (Online)

RMC Memo 26-01: Transition Plan for Implementing Updates to Intermediate Faller (FAL2) Position Qualifications

Intermediate Faller (FAL2) Position Page

NWCG Standards for Wildland Fire Chainsaw Operations, PMS 212

New Aircraft Flight Schedule Form, PMS 249

Date:  April 17, 2026
Questions? 
Please contact: National Coordination System Committee

A new publication from the National Coordination System Committee (NCSC) is now available. The NWCG Aircraft Flight Schedule Form, PMS 249, will be used for aviation crews and dispatch to share flight information that is needed for resource tracking, and if needed, for emergency procedures.

For further details, please contact your NCSC representative. 

References:

NCSC Memo 26-01: Implementation of NWCG Aircraft Flight Schedule Form, PMS 249

NWCG Aircraft Flight Schedule Form, PMS 249

New Glossary Term for Review

Date:  April 15, 2026
Questions? 
Please contact: Data Standards and Terminology Board (DSTB)

The Data Standards and Terminology Board is requesting feedback on a new glossary term: Resource Protection Measure (RPM).

The proposed definition is: Practical guidance provided for incident personnel in a manner in which incident objectives can be achieved while reducing impacts to identified resources across the landscape. RPMs are informed by, but not restricted to, Minimum Impact Strategies and Tactics (MIST).

Please review, share with your subgroups, and provide feedback as appropriate through the following form: Request Feedback The comment period will close May 10, 2026.

Thank you for your engagement in the NWCG glossary process – your participation is key to our success.

References:

Glossary Request Feedback

Quarter Three Materials for the 2025-2026 Wildland Fire Leadership Campaign Now Available

Date:  April 1, 2026
Questions? 
Please contact: Leadership Committee

NWCG is excited to announce that Quarter Three materials for the 2025/2026 Wildland Fire Leadership Campaign are now available. This annual initiative offers all students of leadership and wildland fire management an opportunity to engage with essential leadership skills and knowledge needed to lead effectively in dynamic environments.

Quarter Three materials focus on Leadership Level 3: Leader of People (Develop Intent). Leadership Level 3 is where your values, your team, and your influence come together. Leaders of People put their teams first, build trust, and lead with authenticity. They mentor future leaders and shape decisions up and down the chain.

References:

2025/2026 NWCG Leadership Campaign - Leadership Levels

Wildland Fire Leadership Development Program

Leadership Committee