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Where the Rain Goes

Every river, creek, canal and ditch in the contiguous United States, and the gold lines that settle which sea each one is going to.
2.99Mmiles of stream
2.67Mreaches
56%to the Gulf

Where it all ends up

sq mishare stream mi
the Gulf of Mexico1,687,71456.0%1,720,058
the Pacific416,14213.8%413,084
the Atlantic290,6299.6%277,000
the Gulf of California245,7408.2%271,447
no sea at all190,5096.3%166,062
the Gulf of St. Lawrence126,3744.2%112,793
Hudson Bay56,0361.9%31,219

Why the streams thicken

a first hillside 1,209,807 sq mi above it

Three kinds of parting

2,314 mi the Continental Divide, one ocean from another
7,542 mi the Eastern, the Laurentian and the rest
7,759 mi the rim of a basin with no sea on the far side

Equal area, not Mercator

This is the one map on this site that is not in Web Mercator. At 25° north Mercator stretches a mile by 10%; at 49° it stretches the same mile by 53%, and a map about how much country drains where cannot afford that. It is drawn in Albers, and so is the tile pyramid, so every square inch on your screen is the same number of square miles as every other one, at every zoom. There is no basemap under it.

The print, 36 × 24 inches
Rivers NHDPlus Version 2.1, USGS and EPA, 1:100,000. Divides USGS Watershed Boundary Dataset. Outline US Census. The five Great Lakes are drawn whole rather than cut at the treaty line. ryansajdak.com · © Ryan Sajdak 2026