Great Falls of the Potomac
Rain fedThe Maryland side of the East's wildest urban whitewater, viewed from the Olmsted Island boardwalk off the C&O Canal towpath.
3 documented waterfalls in Maryland, when each one actually runs, and what the river is doing right now where a gauge exists.
Trail status, closures and safety rules belong to each falls' managing agency, named and linked on every page.
Each card carries the typical big-water window drawn from the falls' actual driver, and the latest USGS reading on its feeding river where a gauge exists. The full page for each falls explains the season, shows today against the USGS percentile band, and quotes the managing agency on access.
The Maryland side of the East's wildest urban whitewater, viewed from the Olmsted Island boardwalk off the C&O Canal towpath.
Maryland's Catoctin Mountain cascade, called McAfee Falls by the state's own page, sliding down mossy rock near Thurmont with strictly no swimming or climbing.
Maryland's big one: a crashing 53 foot falls in Swallow Falls State Park's old-growth hemlock corner, with a USGS gauge on the Youghiogheny essentially at the park.
Live readings: USGS Water Services (National Water Information System). Instantaneous values and daily statistics services. U.S. Geological Survey data are works of the United States Government and are in the public domain.
Most of Maryland's documented falls run on snowmelt, so they peak when the high country lets go and fade through the summer. The mix here is 2 snowmelt, 1 rain across the 3, and 2 of them have an active USGS gauge on or near the stream.




Windows are typical-year climatology from each falls' driver, not forecasts. Live readings and percentile bands are USGS data, public domain; where a page says a river is above or below typical, that comparison is ours and is labelled. Access and safety belong to each falls' managing agency, named on its page. National picture →