Difficulty V
Length 0.5 Miles
Flow Range 2.50 - 3.95 FT
Flow Rate as of: 52 minutes ago 2.98 [FT] 👍 ℹ️ ⚠️
Reach Info Last Updated 04/30/2019 6:03 am

River Description


Great Falls of the Potomac River is a major set of rapids located about 15 miles upstream of Washington, DC. The main Falls lines drop fifty feet in one-tenth of a mile, creating a Class V+ set of waterfalls. In addition, a portion of the river flows around Olmstead Island in a channel called the Fish Ladder (additional channels flow at higher water).
The Virginia Line is a classic sequence of technical whitewater leading up to a tricky 20' waterfall.  This channel separates from the main channel at the top of the Flake Island. The top rapid, U-hole is probably the hardest and where most carnage occurs. The ideal line changes depending on the level. 40 years of waterfall hucking haven't made the spout any easier, but boat design probably has. The right line is now the standard line - either boofing over the hole entirely or reconnecting on a shelf. The left line is a good test of boat control. The Virginia side is runnable at high water but not recommended.
Paddlers have known about Great Falls as long as there has been whitewater kayaking. Many of the features -- such as the Spout, the Fingers, the Fish Ladder -- have names that predate paddling, in some cases by hundreds of years. But it was not until paddlers started running waterfalls regularly in the 1970s that paddlers began to seriously consider running the Falls. The first descent of Great Falls was made in 1975 by local experts Tom McEwan and Wick Walker, with the second descent by Steve McConaughy and Great Falls National Park Ranger Bill Kirby.
River Signals and Helicopters
The Park Service patrols the Potomac with a helicopter most summer weekends. In an effort to minimize confusion, the helicopter pilots are trained to recognize three signals from paddlers.
  • Everything OK - Tap the top of your helmet with one hand.
  • Emergency - Wave both arms together over your head (like jumping jacks), holding brightly colored objects if possible.
  • Need Medical Attention - Form an X with arms or paddles.
Don't signal the helicopters unless you need them! And if being inspected, be sure to give the OK sign if you don't need assistance. Sometimes hikers call in "emergencies" that aren't actually emergencies.

Rapid Descriptions


Class - 5.0 Mile - 0.4

Negotiate the small ledges and rocks at the top, then either slide down the left or boof off the center. There's also a high-water sneak on the right called Norman's Leap. The rock shelf protruding from the left bank below the drop is slightly undercut and there can be some very retentive holes


Class - IV+ Mile - 0.45

enter from river left of the nasty hole, boof through an angled ledge, and gnerally stay right. For extra challenge, try catching the 4 eddies.  A short pool separates S-Turn from the Spout, with a convenient staging eddy on the right.

The Spout

Class - 5.0 Mile - 0.5

The Spout is the tallest individual drop in Great Falls at about 18-22 feet with a sloping lip. the current is pushing to the right, curving down a 4' slope, and falling off to the left.

The standard 'old school' line is to start in the river right eddy and  drive hard left across the lip and boof when the ramp ends. Lots of people will inevitable misjudge the current here and end up falling off sideways in the middle....The hole becomes really powerful above 3.1, and a rock behind the curtain (Big Toe) becomes exposed below 2.8.

Many people now prefer the right lines. The far right line involves driving up onto the boil at the lip and boofing onto a rock shelf jutting out from shore. It looks ugly but runs pretty smooth. Skipping off the shelf is actually softer on your back than landing in the green water on the left.

The preffered line is the right of center, boof off the curler, race line. similar to the far right line, but just clipping the edge of the boil, and taking a huge lefty off the curler that falls into the meat of the hole. Run well, this will give you some serious air time but you should  either land clear of the hole or in the seam, reemerging with a mighty salmon jump

The Crack (Class 5.2) is a high-water (3.3 < LF < 3.70) alternate line to the Spout. It requires you to ferry across powerful current and hit a boat-width slot at full speed. If you miss the slot, or get rejected by the boils guarding it, you will wash over the Spout backwards and get destroyed.



default user thumbnail
8 years ago

On July 19, 2008, an attractive blonde lady took great pictures of me on the Spout (of Great Falls) and promised to send them to me, but I never heard from her. This is probably a long shot, but if anyone happens to run into her, or if she sees this, please send pictures to rjsfarmer@yahoo.com, call me at 410-624-6421, or mail me at P.O. Box 41115 Baltimore, MD 21203. I was in an orange boat with red or purple paddles, black lifejacket, and red helmet. Thanks---RF

default user thumbnail
8 years ago

Shiver me timbers, them's some great inoframtion.

default user thumbnail
Scott Anderson
11 years ago

Thanks for your input. As the streamkeeper, I have to use my best judgment when listing river data. The solutions aren't always ideal, but I will try to explain my rationale with regard to gradient. "Please explain how a 1 mile stretch of river can have average gradient of 100 fpm and maximum gradient of 500 fpm." The river drops 100 feet between the put-in and the take-out, which are 1 mile apart. So the average gradient is 100 fpm. However, the heart of the run drops 50 feet in 0.1 miles, for a maximum gradient of 500 fpm. "Maximum gradient figures cited 'up top' should always be computed across a full mile, otherwise they are meaningless." Says who? There is no standard way to calculate gradient. Leland Davis calculates gradient mile by mile in NC Rivers & Creeks, but Stafford and McCutcheon use terms like "200 fpm," "200 fpm action," and "200 fpm crux" in The New Testament. Which is right? Great Falls is a park and huck, so calculating gradient mile by mile would be meaningless. Nobody puts in above Great Falls unless they plan on running it. They're not there for the paddle in and the paddle out. The only section that counts is Great Falls itself, which is 500 fpm. I would put "500 fpm crux" if I could, but the AW page builder doesn't give me that option. Furthermore, removing the 500 fpm maximum gradient from 'up top' could mislead people into thinking Great Falls is no steeper than the Upper Yough. "If you wish to convey that some shorter portion has steeper gradient, you may express that within the text of the description..." The description includes the following statement: "The main Falls lines drop fifty feet in one-tenth of a mile." The reason I include the maximum gradient up top is that nobody reads the description.

default user thumbnail
11 years ago

Please explain how a 1-mile stretch of river can have average gradient of 100 FPM and maximum gradient of 500 FPM. Maximum gradient figures cited 'up top' should always be computed across a full mile, otherwise they are meaningless. If you wish to convey that some shorter portion has steeper gradient, you may express that within the text of the description (as "the river drops 50 feet in a quarter mile, for an effective gradient of 200 FPM") but that should NOT be in the 'Maximum Gradient' area.

default user thumbnail
12 years ago

I was out here the other day to run the Spout. The temperature was supposedly about 93 degrees, but, even though I arrived on Flake Island after sunset, the heat was very, very oppressive. Sitting down to rest did not help, as the rocks were super-heated by the sun to around 120 degrees. I was rapidly becoming seriously dehydrated and probably lost about 30 percent of my strength before putting in to run the rapid. This rapid should probably not be scouted during daylight in the summer. So watch out for the summer heat; I came close to having a heat stroke!!! Also, the water temperature is close to 100 degrees, too, so it provides close to zero cooling.

Gage Descriptions

The VA Lines are most commonly run between 2.9 and 3.1, but they can be run a little lower and certainly much higher if you have enough skill and knowledge of the river.  The limiting factor is usually the Spout.  There's a rock behind the curtain called the Big Toe that comes into play as the level drops below 3.0; one local shattered his elbow on it below 2.8.  Above 3.2 the hole at the base of the Spout gets really violent, These days, most paddlers are running it on the right. At higher water, U-hole and S-turn merge into one  big technical rapid and setting safety is a good idea. Virginia is runnable up to 4 feet but 95% of local paddlers' personal cut off is between 3.1 and 3.4

The gage is located at Little Falls (aka Brookmont) Dam, where the river is very wide.  Consequently, an inch on the gage can translate to a foot at Great Falls.  The gage is also 8-9 miles downstream, so if the river is rising or falling rapidly there could be a discrepancy between the gage reading and the actual level.  Scout the rapids visually if there is any doubt.  (You were going to do that anyway, right?)

USGS Potomac River / Little Falls Gage

NOAA Prediction for Little Falls Gage

Directions Description

Most people park at Great Falls (MD) to run the falls. There is a $5 fee per vehicle to enter the park, or you can buy an annual pass for $20. The MD pass is honored on the VA side and vice versa. You can get directions by typing the address of the Great Falls Tavern Visitor Center into Google Maps or Mapquest:
11710 MacArthur Blvd.
Potomac, MD 20854
No shuttle is necessary. When you finish running the Falls, continue downriver and take out at Sandy Beach. Then walk back to your car via the towpath.

Date Flow Result Factor  
1981-09-20 Low Near Miss/Rescue Other Read More



article main photo

Upper Yough Access Guidelines and Fundraiser

Charlie Walbridge

At Maryland's Upper Yough, one of the country's finest whitewater runs, American Whitewater has been maintaining the Sang Run Access for the past 20 years. With the 4th of July weekend coming up, a quick reminder that we are guests of the Town of Friendsville when we take out. In addition changing clothes discretely ad behaving respectfully, please observe social distancing during the pandemic. Garrett County has a low infection rate, and a mask when patronizing local businesses is the norm. We are also beginning our annual fundraiser to pay the expenses American Whitewater has at Sang Run. Out goal is $1,000, and we have already received $160. The Fee Box at Sang Run is still closed due to vandalism. We suggest $20 for the full season; $5 for one weekend. Please donate on line, or use the donation jar at the Wilderness Voyageurs shop at the takeout. Please go to https://www.americanwhitewater.org/content/Membership/donate/? and put "Upper Yough Access" in the comment box.

article main photo

Don Millard - AW Super Upper Yough Access Volunteer!

Charlie and Sandy Walbridge

American Whitewater super-volunteer Don Millard has been taking care of the Sang Run and Friendsville Access Areas on Maryland's Upper Youghioghenny River for the past several years. This bulds on a 2003 agreement between American Whitewater and Maryland State Parks, which owns the property. This year he rebuilt the change house and porta-pot shelter, set AW's sign back up, filled in potholes, and mowed acres of grass. He not only did the work, he donated the materials and machine time! This work givezs AW strong ties to the community (the place is also a fishing access) and local park managers. Also, thanks to him, boaters are not faced with a $5 access fee at both ends! Please remember, the pandemic is still on. Be smart. If you use the porta-pot, wash your hands or use sanitizer!

article main photo

2010 Potomac Fest - July 10-11 (MD/VA)

Kevin Colburn

Come see American Whitewater at this year's Potomac Fest, July 10 and 11 in Great Falls, MD/VA!  Just minutes from the Nation's Capital, the 20th Annual Potomac Whitewater Festival will be two days of fun events organized to delight beginners, experts and spectators alike.

article main photo

Attention Virginia Boaters!

Jason Robertson

During the high waters of Spring 2003, there has been a noticeable increase in reported confrontations between boaters and property owners in Virginia. Please remember to be respectful and courteous to property owners; do not trespass; and avoid confrontation in order to preserve access in the future.

Geoff Calhoun


Scott Anderson


Matt Muir


Revision #Revision DateAuthorComment
1202339 06/23/13 Geoff Calhoun
1201695 12/03/12 Scott Anderson Downgraded the Spout from class 5.1 to 5.0 after consulting list of AW standard rated rapids and conducting survey of Great Falls locals. However, the VA lines will keep the class V+ rating overall.
1202340 06/23/13 Geoff Calhoun
1200618 09/07/11 Matt Muir Added 2nd state; reordered.
1202341 06/23/13 Geoff Calhoun gc
1206891 10/03/16 Matt Muir gc
1212088 04/30/19 Matt Muir updated image position
1194807 09/20/20 n/a n/a