The USGS GNIS placename database was used to make this map. Any stream whose name ends in "Branch" gets a purple dot, any whose name ends in "Run" gets a green dot, and any whose name ends in "Brook" gets an orange dot. Stream names that end with other terms, like "River" or "Bayou" are not shown.

This map shows a strong geographic pattern in the use of these stream terms. "Brook" occurs mostly in New England and New York. "Run" is confined mainly to Pennsylvania, Ohio, and northern West Virginia. "Branch" is common in the South, including Missouri. Indiana, Maryland and Appalachian Virginia use both "Branch" and "Run". New Jersey uses all three terms. There are other curious patterns, such as a cluster of "Branches" in southwest Wisconsin and "Brooks" in Minnesota. All three terms are rare in the West.