The One Minute Geographer: The Great Plains - The 100-Degree West Longitude Line

The 100th meridian in yellow; rainfall — red; elevation — blue; and grasslands — green. Base map from whatsansweer.com; lines drawn by the author.

The 100-degree west longitude line, the 100th Meridian (yellow on the map), is a fascinating line because it happens to closely coincide with other important geographical features of the United States.

Those other features include the 20-inch rainfall line (red), the line very roughly marking 2,000 feet of elevation (blue), and…