This photo needs editing.
Difficulty IV+
Length 1.9 Miles
Flow Range CFS
Flow Rate as of: 1 second ago N/A
Reach Info Last Updated 04/05/2020 11:19 pm

River Description

This short run is just the tail end of the Patterson Bend run, but the K1 parking lot provides a fairly convenient access point.   In the past the K1 powerhouse would release up to 1750 cfs during the fall when the  Kerchoff #2 powerhouse is shut off for maintanence.   However, the K1 powerhouse is old and PG&E has chosen cease generation there.  Now, when K2 is down for maintenance any flows in the river will be spilled from Kerchoff Dam at the top of the Patterson Bend Run.  Boaters might still choose to do this short run if they have only a little time.

Getting there: From Fresno, take highway 168 into the foothills. Turn left on Auberry Road to the town of Auberry. In Auberry, veer left onto Powerhouse Road at a fork next to the school. From Auberry, follow Powerhouse Rd. just a few miles to a left turn onto Smalley Rd. There should be signs for the "San Joaquin River Gorge Recreation Area" (SJRGRA) which is owned by the BLM. Follow Smalley Rd. to the very end which is the take-out. A gate and some parking areas indicate that you are on top of the underground Kerchoff #2 powerhouse. Walk down the river access trail if you wish to inspect the end of the run.  This trail reaches the river near the top of the last rapid.

Put-in: From the take out parking at the end of the road, backtrack 1.5 miles and turn left at a junction. Immediately park at a parking area as the road may be gated just beyond. From here you must carry down to the old powerhouse. Carry around the first gate and follow the road towards some sheds, (1/4 mile). Just before the sheds another gate blocks a narrow road dropping off to the left down to the powerhouse (4/10 mile). From the parking lot at the powerhouse, descend next to the fence, then climb down an awkward 50 feet to the river.

If the gate is open, you can park near the visitor center, then hike down the road to the powerhouse, or park past the visitor center and find a way down the hill upstream of the powerhouse.

Take-out: Drive to the very end of Smalley Rd. and park outside a gate. The transformer station and high tension lines indicate that you are on top of the new underground powerhouse. On the river, paddle a last long class 4ish slalom and eddy out on river left in the channel below the outlets from the underground powerhouse. Carry back upstream and look for a trail heading steeply up the hill. 
google map


General description: For a warm up at the put-in, paddle upstream past the powerhouse till your path is blocked by boulders. Paddling downstream, pass under a bridge and then enter a fairly long class 2-3ish rapid. The horizon line of a steep class 4, follows immediately. Worth scouting to see the best lines. A nasty hole is at bottom left. A long pool and big boulders follow. Next rapid is a narrow chute on river right. Stay on the tongue. The right side hole and eddy seems to keep boats and swimmers. A long pool leads to the upper falls, a huge boulder blocking the entire channel. Scout or portage on river left. Run a tight creekish route on far right. Scout the lower falls on river right. Portage is very difficult. Run or ski jump a center falls, then run the chute down the left wall. A nasty hole blocks the center and right side at the bottom of the chute. This hole will send you very deep. A long pool allows you to pick up any pieces. (the right chute has been run I think, but looks very ugly and the bottom center boulder is massively undercut on that side.) Several short but interesting class 3 - 4 rapids occupy the remainder of the gorge. The river bends to the left and opens up, then a wonderful long class 4 slalom finishes the run. Boaters can continue down into the Millerton Bottoms run if they are willing to deal with the take-out issues of that section.

The parking area at SJRGRA is about 1,000 feet elevation, with lots of Oaks, grass, brush, and a few pines. There are toilets, picnic tables, and now, even potable water. Camping is free. It is a popular area in fall, winter and spring, for horse back riding, hiking and mt. Biking. Groceries, gas and food are available in Auberry and Prather.

For more information about the SJRGRA see: SJGRA

Information about Millerton Reservoir State Rec Area is available at Millerton SRA

PG&E Kerchoff Project - FERC Relicensing:
The PG&E Kerchoff Project, FERC project No. 96 was last relicensed on Nov. 8, 1979. The license expires on Nov. 30, 2022. The project consists of the small Kerchoff dam &reservoir, and the two powerhouses. The generators at the two powerhouses have a combined rated maximum capacity of 174,075 KiloWatts.  PG&E has informed Ferc in 2019 that they will no longer generate power at K1 and will officially decommission it.  The building will remain and will be put to other purposes. Search for FERC documents related to Kerchoff at  In the Docket Number box, write P-96-* to do a wild card search for any documents related to Project 0096.

The relicensing process typically starts about 4 years ahead of time, so will likely start in 2018.  In this process, AW will advocate for scheduled releases from Kerchoff Dam to facilitate whitewater boating in Patterson Bend, K1 to K2 and Millerton Bottoms.  We will also advocate for real time flow information below Kerchoff #2 when Millerton is low enough for boating in the Millerton Bottoms section.

Temperance Flat Dam:Temperance Flat Dam Proposal:  
This area of the San Joaquin is presently under study for a large dam and reservoir. See:
Upper San Joaquin Basin Storage Investigation Three sites were under serious investigation. As of 2014, the final selected site is about one mile upstream of the confluence with Finegold Creek and would have a maximum size of around1.4 million ac/ft.  Despite the large size maximum annual yield is around 100,000 ac/ft. This reservoir will bury the Patterson Bend, K1 to K2 and the Millerton Bottoms sections. The study has maps and updates on the proposal.

Draft EIS is out September 2014.   Comments are due by October 27, 2014.   Send comments to:  Melissa Harris

Friends of the River: Dam Facts, Dam Lies, and Statistics

Friends of the River     Letter to Governor Schwarzenneger opposing new dams.




Rapid Descriptions

Kerchoff #1 Powerhouse

Class - Mile - 0
Rapid Thumbnail Missing
The road to the powerhouse is usually gated. Even if it is not, don't park down there. Park at the main lot to the right of the main intersection. Carry 2/10 of a mile to the educational center then turn right down past another gate and go 4/10 of a mile to the powerhouse. From the powerhouse parking area it is a short but steep and awkward carry down to an awkward launch point on the river. Ropes can be handy and will be necessary for rafts.

First rapid

Class - III Mile - 0.13
Rapid Thumbnail Missing

After passing under the hiking bridge, enter a long easy class 3 rapid that provides a good warm up.
at 850 cfs

Second rapid

Class - IV Mile - 0.25
Rapid Thumbnail Missing

The tailwaves of the first rapid extend very close to a big wide horizon line above this short but steep drop. The right and middle tend to be blocked by barely submerged rocks, or not submerged rocks at 900 cfs. A deep hole blocks the bottom left.
at 850 cfs

at 4200 cfs, the rapid is still pretty meaty!

3rd rapid

Class - III Mile - 0.57
Rapid Thumbnail Missing

Float through a pleasant maze of huge boulders till you come to an intimidating horizon line.  Boulders block the channel, leaving a steep narrow chute on river right. Scout from river left. Run the middle of the tongue through the chute. Holes lie on both sides. The right side hole and eddy can potentially trap swimmers and gear. Rescue by rope can be necessary
at 850 cfs

Upper Falls

Class - 5.0 Mile - 0.7
Rapid Thumbnail Missing

A huge boulder blocks the channel. At typical Fall flows of 1,800 cfs or less it is possible to scout and portage on river left. A tight tricky line can be boated around the right side of the boulder. The left side is a nasty siphon.
at 4300 cfs

If Patterson Bend is running, it will be necessary to scout or portage on river right with much greater difficulty. Both sides of the boulder will have large holes, but boaters can boof off the boulder to skirt the edge of the right side hole.
at 4300 cfs

Lower Falls

Class - 5.0 Mile - 0.78
Rapid Thumbnail Missing

A cluster of boulders block the entrance to this long rapid. Scout river right. At typical Fall flows, it is fairly easy to get out and scout, but portage requires climbing over boulders, and then along an awkward cliff. The portage route basically ends a few feet before the rapid ends, so it takes creativity and courage to reenter a boat.. Good climbers can help others across to a ledge in the pool below. You should consider this rapid a mandatory run. The entrance is a short waterfall in the center. You can boof the left edge, but old timers just ran down the tongue and got away with it. There is a strong boil and outlflow which shoots you to the left.
850 cfs vs. 4500 cfs

Paddle across a short pool to the left channel and charge over a series of ledges. A very sticky hole occupies the right side of this channel at the bottom. Hit it on the left or swim. The right side channel looks ugly but has supposedly been run. The huge boulder seperating the channels at the bottom is completely undercut. The room visible underneath at fish flows is very big. If Patterson Bend is running it will not be easy to exit a boat and scout, so it may take a team effort to get one person out to where they can see the routes. Fortunately, at high flows, a clean route opens up against the left wall. Just stay in the chute against the left wall through the whole rapid.
at 4700 cfs

5th rapid

Class - III Mile - 0.97
Rapid Thumbnail Missing

Boat scoutable. A moderate swirling rapid is followed by a nearly river wide hole. The hole is easy to avoid but is impressive.
at 850 cfs

6th rapid

Class - III Mile - 1.1
Rapid Thumbnail Missing

Boat scoutable. A relatively long and straight chute piles into a big jagged boulder. It is easy to stay to the right, but exciting anyway.

7th rapid

Class - II+ Mile - 1.3
Rapid Thumbnail Missing
This simple drop has a wide clean tongue.

8th Rapid

Class - III Mile - 1.4
Rapid Thumbnail Missing

A cluster of boulders block the view, causing worry. Paddle to the first eddy and the rest of the rapid becomes visible. There can be some good play spots at the bottom of this rapid even for long boats. A small but retentive hole is on river left. The left edge of the nearby rock can provide nose stands for big boats.

Flat water leads around the corner towards Slalom rapid, but a little ways before there is a short drop past two holes. At some flows there is a decent surf wave below.




Class - III+ Mile - 1.6
Rapid Thumbnail Missing

The last rapid in this section is a long slalom that weaves between several large holes. It finishes with a nice wave train ending at the slackwater from the Kerchoff #2 powerhouse. It is pretty easy to carry back upstream and run this rapid as many times as you want. Also, a trail up to the parking area starts near the top of this rapid.

Kerchoff #2 powerhouse

Class - Mile - 1.8
Rapid Thumbnail Missing
Take out in the slackwater at the outlet from this underground powerhouse. Carry back upstream a short ways to either trails or the road leading up to the parking area. It is a steep tedious carry no matter what.


Gage Descriptions

In 2008, flows are expected from Nov. 9 through Friday Nov. 14.

In 2007, flows did not occur due to Kerchoff dam maintenance
In 2006, flows were from mid October to Friday November 17.
In 2005, flows ended on Friday Nov. 18th.
In 2004 the window ended on November 19.
In 2003 the flow window started on Saturday November 8 and ran through Dec 5.

Local whitewater representatives must contact PG&E each year to find out approximately from what date to what date the Kerchoff #1 powerhouse will be in operation in the Fall. Once they report which weeks the powerhouse is in operation, the following information can indicate what times during the day it is operating.


To estimate what times the powerhouse is running, Look at the daily fluctuations or slope changes on the Millerton Elavation Graph. When the slope is donwards inflow is less than outflow. When the slope is level, inflow is equal to outflow. When the slope is upwards, inflow from the powerhouse is higher than outflow from the reservoir. The most up to date inflow and outflow numbers are 24 hour averages from the previous day, available after midnight at Millerton daily report (pdf). Look at the total average release from Friant Dam and that number is what the inflow has to be whenever the graph above is level. Also look at the inflow number on the daily report. If the number is around 1,000 cfs then the old powerhouse should be running close to 24 hours a day. As the total inflow drops lower than that amount, the powerhouse is probably operating for fewer hours (rather than lower flows). If inflow is greater than 1,000 cfs, then it is likely that some spill is occuring in Patterson Bend. (In the past this powerhouse consistently released around 1,700 cfs, but in recent years the maximum output seems to be around 1,000 cfs. P.M. - 2006)

As stated above, inflows to Millerton are an indication of flows in K1 to K2 only for a few weeks each fall, when the Kerchoff #1 Powerhouse is operating. The rest of the year, inflows indicate releases from Kerchoff #2 powerhouse into the Millerton Bottoms section. . The USGS links for the two powerhouses show historical data and show what dates the powerhouses were on or off in previous years.

The Millerton Stats page also gives information about the reservoir, including a 24 hour average inflow (though always 2 days late).



Directions Description


No Accident Reports



article main photo

Prevent a New Dam on the San Joaquin (CA)

Theresa Simsiman

We need your help to protect the San Joaquin River! The proposed Temperance Flat Dam would drown an incredible river canyon that the Bureau of Land Management (BLM) has already recommended for Wild and Scenic River designation. Despite the enormous price tag of at least $2.6 billion, according to the Bureau of Reclamation's preferred alternative for the project, the dam would only yield 70,000 acre-feet of water per year on average. Take action today.

article main photo

New and Bigger Dams Threaten California Rivers

Evan Stafford

California is emerging from a multi-year drought and numerous dam proposals threaten rivers throughout the state. These proposals do little to address the state's water concerns and come with a hefty price tag. American Whitewater is focusing efforts to stop these unnecessary surface storage projects.

article main photo

American Whitewater Opposes Temperance Flat Dam (CA)

Megan Hooker

American Whitewater submitted comments this week to the Bureau of Reclamation in opposition of the proposed Temperance Flat Dam slated for the San Joaquin River in California. The proposed dam would inundate a reach of river that the Bureau of Land Management recognized as suitable for inclusion in the National Wild and Scenic Rivers System for its cultral and scenic values. Temperance Flat Dam will have steep economic and resource costs while yeilding little water, and is not the solution to California's extreme drought.


Paul Martzen


Theresa Simsiman


Revision #Revision DateAuthorComment
1214583 04/05/20 Paul Martzen updated description
1209911 06/20/18 Theresa Simsiman Remove offensive name as requested by the tribe
1209909 06/20/18 Theresa Simsiman Remove offensive name as requested by the tribe
1209912 06/20/18 Theresa Simsiman Remove offensive name as requested by the tribe
1209905 06/20/18 Theresa Simsiman Remove offensive name as requested by the tribe
1209908 06/20/18 Theresa Simsiman
1213782 10/04/19 Paul Martzen updated description
1213781 10/04/19 Paul Martzen updated description
1209913 06/20/18 Theresa Simsiman Remove offensive name as requested by the tribe
1193986 11/08/08 Paul Martzen n/a
1203725 10/14/14 Paul Martzen Temperance Flat Dam - update
1203726 10/14/14 Paul Martzen Temperance Flat Dam - update