The St. Mary and Milk Rivers cross the U.S. and Canadian border and supply water to both countries. Managing that resource in the interest of both nations is a matter of international collaboration and cooperation, and Landsat data is helping offer objective information on water use. On today’s episode of Eyes on Earth, we hear from Roy Sando of the USGS, who’s working with EROS experts and the International Joint Commission to turn Landsat-based evapotranspiration (ET) estimates into a tool for farmers and land managers on both sides of the border.