Welcome to launch. We are currently expanding our databases quickly — user input and corrections are needed and appreciated. The content and functions on this site are deep. If you find something that is out of order, please let us know.
Maryland · Montgomery Co.

Potomac River — Great Falls

Montgomery Co. · 14 mi · Class II–V
Optimal: 2000–12000 CFS · USGS #01638500
Water temp: 81°F
8,200 avg
2,610CFS
1.34 ft gauge height
Optimal
Rising slowly (+20 cfs/hr)(+70 in 3h)
Flow data is live from USGS·Rapid classifications and CFS ranges need community verification·Know this river?
Avg flow: 8,200 cfsHist. median: 7,380 cfsUSGS #01638500
Great Falls Park (NPS) · C&O Canal National Historical Park · Potomac Heritage Trail

About

Class V drops at Great Falls compress the Potomac through a granite gorge that expert kayakers portage and scout extensively before running. Below the falls, Mather Gorge to Carderock stretches through Class II-III water that draws paddlers from Washington and Baltimore when flows hit the 2,000-12,000 CFS sweet spot. The 14-mile corridor through Montgomery County averages 8,200 CFS on USGS gauge 01638500, with spring floods pushing much higher. Great Falls Park and the C&O Canal National Historical Park protect both banks, while commercial outfitters like Liquid Adventures and Calleva run guided trips through the lower gorge sections. The granite geology that creates the falls continues downstream as Mather Gorge, where Class II-III rapids funnel between 50-foot walls. Carderock is the standard takeout before the river opens into the tidal Potomac near Washington.

Solunar Fishing Activity
🌒
Waxing Crescent
15% illumination
Poor
Moon overhead
8:37 AM
Moonrise
1:13 PM
Moonset
4:02 AM
Moon underfoot
8:37 PM
Next full moon: May 3111 days
Outfitters
Liquid Adventures
Potomac kayak instruction and Great Falls trips
Calleva
Potomac River kayak and canoe programs, Poolesville
10-Year Flow Patterns
See 10 years of flow patterns for this river — historical analysis is a Pro feature.Upgrade to Pro →
Your Optimal Range
Set your personal optimal CFS window per river — custom ranges are a Pro feature.Upgrade to Pro →
Data Quality

River conditions are community-verified. CFS ranges, difficulty ratings, and access points may not reflect every flow level or seasonal change. Always check current conditions, scout unfamiliar rapids, and paddle within your skill level.

Know the Potomac River — Great Falls? Your local knowledge makes this page better for every paddler, angler, and guide who comes after you.
Improve This River →