Tracking Creatures of Bavarian Folklore Using a Least-Cost Path Model

A colorful pattern representing overland costs.

Author: Nicolas R. Malloy

Table of Contents

  1. Tracking Creatures of Bavarian Folklore Using a Least-Cost Path Model
  2. Setting up Your Workspace
  3. Preparing the Data
  4. Skill Drill: Geocoding an Address and Creating a CSV Table to Import As XY Data
  5. Skill Drill: Defining the Study Area
  6. Skill Drill: Acquire Elevation Data from the USGS National Map Viewer
  7. Skill Drill: Acquire Land Cover Data from the USGS National Map Viewer
  8. Skill Drill: Acquire Hydrography Data from the USGS National Map Viewer
  9. Changing Global Environment Settings for Raster Processing
  10. Creating Cost Surface Models Using a Relative Cost Scale
  11. Creating a Remap Table to Reclassify Elevation
  12. Skill Drill: Creating a Remap Table to Reclassify Slope
  13. Skill Drill: Creating a Remap Table to Reclassify Tree Canopy Density
  14. Converting the Hydrography Features to Cost Surface Models
  15. Creating a Total Cost Surface Model
  16. Creating a Cost-Distance Surface Model
  17. Creating a Migration Corridor
  18. Determining the Least-Cost Path
  19. Skill Drill: Creating a Map of the Results

In this lab, you will explore modeling overland paths using a least-cost path model. You will create a series of distance, directional, allocation, and cost surface models, which will allow you to create least-cost paths and wildlife corridors.

Estimated time to complete this tutorial: 6 hours

Learning Outcomes

  • Review how to acquire data from a public source
  • Geocode an address
  • Review adding XY data
  • Review Data Management Tools: project, define projection
  • Review Spatial Analyst tools: Slope, Raster Calculator, & Reclassify
  • Create a remap table
  • Create a composite cost surface raster
  • Create a cost distance raster
  • Model least-cost path
  • Model a migration corridor


In this scenario, a dedicated group of graduate students from Humboldt State University spent last summer in the Redwoods State Park near the town of Orick, maintaining a high level of beer consumption, collecting data on an elusive creature described in Bavarian folklore as the wolpertinger.

An illustration of the wolpertinger by Albrecht Durer, 1502
Illustration by Albrecht Durer, 1502

Bavarian folklore portrays the wolpertinger as a fanged animal with the head of a rabbit, the body of a squirrel, the wings of a pheasant, and the antlers of a deer. The wolpertinger is thought only to be visible to persons who have consumed large amounts of beer. During their stay in Redwoods State Park, the HSU students documented many sightings, located several wolpertinger dens, and later discovered an annual migratory behavior. It seems that in the fall, around late September and early October, sightings of the creature significantly increase near towns and villages. The wolpertinger prefers areas of high elevation and steep slopes to avoid predators. They also prefer areas covered by a dense forest canopy. Wolpertingers also avoid crossing deep rivers and lakes during periods of migration. You will predict the overland movement of the wolpertinger using the following cost factors in your analysis:

  • Elevation
  • Slope
  • Tree canopy density
  • Hydrology

Conduct this analysis using the Universal Transverse Mercator (UTM) system along with the North American Datum of 1983 (NAD83). Humboldt County lies in Zone 10 of the UTM system. All of your data must be in this spatial reference system at the start of your analysis. Create working copies of your data in this spatial reference system using the Project Raster tool in ArcMap as needed.