Creating a 7.5-Minute Topographic Basemap Series

Skagit County departments expressed a desire to have general maps quickly available for search and rescue, emergency response, and basic project planning. The goal for Skagit County GIS was to provide up-to-date maps in a familiar format that had the look and feel of the USGS 7.5-minute quadrangle maps. The maps were created using existing data such as the National Land Cover Database for vegetation, county assessor data for residence locations, and Skagit County’s GIS data for roads and place-names. The surrounding location grid was updated to include the United States National Grid (USNG) coordinates along with latitude and longitude lines. A separate cover sheet contains detailed information such as the legend, explanations of how to use the USNG grid, and disclaimers. There are 40 maps in the series, produced using DS Mapbook and Esri Maplex extensions for labels. No annotation was used, so the dynamic labeling allows future maps to be created at different scales and extents and also to be replicated in the county’s public ArcIMS site.

Courtesy of Skagit County, Washington.