Winter Storm Warning
2026-05-06T15:00:00-06:00

* WHAT...Heavy snow expected. Total snow accumulations between 5 and 8 inches with locally up to 12 inches next to the foothills. * WHERE...Fort Collins, Boulder, Denver metro area, and Castle Rock. * WHEN...From 8 PM this evening to 3 PM MDT Wednesday. * IMPACTS...Heavy snow accumulating on trees may result in broken tree limbs, downed powerlines, and scattered power outages. Despite lesser accumulations on roadways, slick and hazardous conditions are still possible for the Wednesday morning commute.

Casselman River

Last Updated: May 5, 2026

Total streamflow across the Casselman River was last observed at 531 cfs, and is expected to yield approximately 1,053 acre-ft of water today; about 45% of normal. River levels are low and may signify a drought. Average streamflow for this time of year is 1,188 cfs, with recent peaks last observed on 2025-05-14 when daily discharge volume was observed at 29,280 cfs.

Maximum discharge along the river is currently at the Casselman River At Markleton reporting a streamflow rate of 445 cfs. This is also the highest stage along the Casselman River, with a gauge stage of 1.95 ft at this location. This river is monitored from 2 different streamgauging stations along the Casselman River, the highest being situated at an altitude of 2,135 ft, the Casselman River At Grantsville.

The Casselman River is a 56-mile long tributary of the Youghiogheny River located in western Maryland.


15-Day Long Term Forecast


River Details

Last Updated 2026-05-05
Discharge Volume 1,053 ACRE-FT
Streamflow 530.7 cfs
Past 24 Hours: -70.7 cfs (-11.76%)
Percent of Normal 44.69%
Maximum 29,280.0 cfs
2025-05-14
Seasonal Avg 1,188 cfs
       
River Streamflow Levels
Streamgauge Streamflow Gauge Stage 24hr Change (%) % Normal Minimum (cfs) Maximum (cfs) Air Temp Elevation
Casselman River At Grantsville
USGS 03078000
86 cfs 1.38 ft -11.1
Casselman River At Markleton
USGS 03079000
445 cfs 1.95 ft -11.88
Seasonal Discharge Comparison
Maximum Streamflow Discharge
Streamflow Elevation Profile

The Casselman River is a 56.5-mile-long (90.9 km) tributary of the Youghiogheny River in western Maryland and Pennsylvania in the United States.The Casselman River rises in Garrett County atop the plateau of western Maryland as two branches, the south one east of Meadow Mountain, the north one farther west, between Meadow Mountain and Negro Mountain. The two branches flow northward combining just southwest of Grantsville, Maryland. The river then continues north into Pennsylvania, following a great arc across the Laurel Highlands of Somerset County, Pennsylvania to the community of Confluence, where Laurel Hill Creek joins a few meters above the Youghiogheny River.The river has been used for transportation across the Allegheny Mountains, between the cities of Baltimore and Washington, D.C. in the east and Pittsburgh in the west. Two railroads followed the Casselman River from Meyersdale, Pennsylvania to Confluence. First is the B&O Railroad, running between Baltimore and Pittsburgh, which was completed in 1827, and is currently owned by CSX. Second is the Western Maryland Railway, which ran from Cumberland, Maryland to Connellsville, Pennsylvania. Although the Western Maryland was abandoned in the 1980s, the right-of-way has been converted into the Great Allegheny Passage, a rail trail bicycle and hiking path.