Kearns

The United States has more than 90,000 dams on its rivers. Many of them no longer generate power, hold back floods, or serve a purpose at all. They just sit there, aging, holding the water back. Take one out, and the ecological recovery can happen breathtakingly fast. In 2024, the largest dam removal in American history finished on the Klamath River, where four dams came down along the Oregon-California line. Within days, Chinook salmon were pushing into water they hadn't reached in generations. By the fall of 2025, they had climbed all the way into the upper basin, spawning in streams that had been sealed off for more than a hundred years. Damon Goodman, a regional director for California Trout, put it plainly: the rivers "seem to come alive almost instantly after dam removal." Maine's Penobscot tells the same story. After two dams came down, the river herring went from a few thousand fish a year into the millions, and with them came back the eagles, ospreys, and otters that live off the run. A dam is one of the few environmental problems you can fix by subtraction. Take the wall away, and the river seems to remember what it was.