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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

2025/2026 Leadership Campaign Quarter 2 Now Available!

Date: February 13, 2026
Questions? 
Please contact: Leadership Committee

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

This quarter focuses on Leadership Level 2: New Leader (Conveying Intent). Conveying intent is a crucial leadership competency in the high-risk, dynamic environment of wildland firefighting. Months 4 - 6 will concentrate on how successfully conveying intent enhances situational awareness, promotes shared understanding, and empowers firefighters to exercise initiative and adapt to changing conditions.

References:

2025/2026 NWCG Leadership Campaign - Leadership Levels

Wildland Fire Leadership Development Program

Leadership Committee

Opportunity to Serve the Wildland Fire Community as an IPTM SME!

Date: February 10, 2026
Questions? 
Please contact: NWCG SME Specialist

NWCG is seeking experienced wildland firefighters and support personnel to serve as Subject Matter Experts (SMEs) for the Incident Performance and Training Modernization (IPTM) initiative. The intent of IPTM is to transition NWCG’s training and qualification system to a performance-based model through updated position descriptions, Incident Position Standards, Next Generation Position Task Books (Next Gen PTBs), and updates to training where needed.

NWCG is currently recruiting SMEs for the following positions:

  • Aircraft Timekeeper (ATIM)
  • Compensation/Claims Unit Leader (COMP)
  • Cost Unit Leader (COST)
  • Crew Representative (CREP)
  • Deck Coordinator (DECK)
  • Fire Effects Monitor (FEMO)
  • Field Observer (FOBS)
  • Geographic Information System Specialist (GISS)
  • Ordering Manager (ORDM)
  • Receiving/Distribution Manager (RCDM)
  • Staging Area Manager (STAM)

Projects begin April/May 2026 and require 15–20 hours per month for 6–8 months, including a five-day workshop in Boise, Idaho this May. Apply by February 27, 2026, at the link below and review the attached document for details.

References:

NWCG SME Interest Sign-up

IPTM Subject Matter Expert Duties and Expectations Document

Incident Performance and Training Modernization (IPTM)

NEW! M-280, Resource Advisor, Fireline (Instructor-Led) Course Available Now

Date: January 29, 2026
Questions? 
Please contact: Resource Advisor Subcommittee

NWCG is pleased to announce the new M-280, Resource Advisor, Fireline (Instructor-Led) course is now available. This training supports individuals working towards Resource Advisor, Fireline (REAF) incident qualifications.

M-280, Resource Advisor, Fireline (Instructor-Led) training prepares students to serve as a Resource Advisor, Fireline (REAF) as defined in NWCG Incident Position Standards for Resource Advisor, Fireline, PMS 350-112. This course presents scenarios that reflect the diverse challenges a REAF may encounter during an incident. Through these scenarios, participants gain hands-on experience and an understanding of REAF responsibilities in a controlled learning environment.

References:

Resource Advisor, Fireline Position Page

NWCG Position Standards for Resource Advisor, Fireline, PMS 350-112

M-280, Resource Advisor, Fireline (Instructor-Led)

Wildland Fire Learning Portal

2026 Updates to the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1

Date: January 23, 2026
Questions? 
Please contact: Incident and Position Standards Committee

The Incident and Position Standards Committee has updated the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1.

These updates address changes to incident position names and requirements for qualification, training, and experience. Updates related to the implementation of Complex Incident Management (CIM) and Incident Performance Training Modernization (IPTM) are also included.

The NWCG Wildland Fire Position Qualification Flowchart, PMS 308 has also been updated to reflect the recent changes.

References:

NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1

NWCG Wildland Fire Position Qualification Flowchart, PMS 308

IPSC Memo 26-01: January 2026 Updates to the NWCG Standards for Wildland Fire Positions Qualifications, PMS 310-1