About this river
Casselman River is a 23.1 mile river near Deep Creek Lake Boat Rentals in Maryland. Streamflow is measured at the USGS gauge Casselman River at Markleton, PA (site 03079000). The National Hydrography Dataset places it at stream order 6. Reach geometry comes from the USGS National Hydrography Dataset.
Typical flow by month
1921 to 2025
Casselman River typically runs highest in March, at a median 1,020 cfs, and lowest in September, at 76 cfs. The highest flow on record for any single day is 25,000 cfs, in 1996.
| Month | Typical (cfs) | Usual range (cfs) | Relative level |
|---|---|---|---|
| January | 555 | 290 to 1,040 | |
| February | 631 | 355 to 1,250 | |
| March | 1,020 | 628 to 1,730 | |
| April | 815 | 529 to 1,310 | |
| May | 595 | 342 to 1,040 | |
| June | 257 | 161 to 529 | |
| July | 147 | 85 to 294 | |
| August | 103 | 60 to 203 | |
| September | 76 | 41 to 173 | |
| October | 97 | 57 to 248 | |
| November | 277 | 115 to 550 | |
| December | 520 | 270 to 940 |
Typical is the median of each month’s daily median values, and the usual range runs from the median 25th to the median 75th percentile, across about 104 years of record. Statistics published by the US Geological Survey for Casselman River at Markleton, PA (site 03079000). Conditions on any given day can fall well outside the usual range. Check the current reading before you go.
Boat access nearby
3 mapped launches sit in the mapped area of Casselman River, all of them public access. Ramp data comes from the USGS national boat-ramp inventory.
Embed this gauge on your site
Paste this snippet anywhere, an outfitter page, a club site, a trip report, to show Casselman River's live streamflow, water level and 7-day trend. It reads the USGS gauge directly, updates itself, and links back here.
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