San Joaquin
4. Patterson Bend (Kerckhoff Reservoir to Kerchoff #1 PH)
| Difficulty | III-V |
| Length | 11.6 mi |
| Avg Gradient | 33 fpm |
| Permit | No permits are needed to run the river. Parking permits are required by BLM at the take out. |
| Gauge | San Joaquin River Near Auberry |
| Flow Rate as of 1 hour | 44 cfsbelow recommended |
| Reach Info Last Updated | April 16, 2024 |
Projects
The San Joaquin River is one of California’s most significant whitewater rivers, flowing from the high Sierra Nevada through the steep granite walls of the San Joaquin River Gorge Special Recreation Area. It is also one of the most intensively developed hydropower rivers in the state. For over two [...]Read More
The BLM has determined that the San Joaquin River Gorge is eligible for inclusion the National Wild and Scenic Rivers System.
River Description
Patterson Bend has a reputation as a hard run because of the old write up in the Holbeck & Stanley guidebook. By modern standards it is a pretty moderate run. Unfortunately, dependable flows are rare enough that boaters don't get a chance to see what it is really like. The scenery is outstanding and most of the rapids are in the class 3 range. There are a number of wonderful class 4 rapids along the run, but only three class 5 rapids in Patterson Bend, plus two more down in the K1 to K2 section. At moderate flows, all rapids are pool drop with long catch pools below.
The first big caveat is that it requires work to do this run. It requires work to paddle two miles across Kerchoff reservoir, then carry around the dam. It is work to hike up to your car at the end. It requires lots of work to get around Binocular Rapid if you choose not to run it. It is easy to spend an hour or more if you portage. It can take quite awhile just to scout.
The second big caveat is that when this run does get spill, the flows are much more often high than moderate. Also flows can fluctuate from moderate to high, quickly and frequently. Most of the run is probably really good at high flows, but the big rapids pose serious issues for scouting, running or portaging.
Prior to 1982 and the construction of the big Kerchoff #2 powerhouse, this section had dependable flows through the summer. The old timers got to boat it a lot. After 1982 flows became rare and it was nearly impossible to know when they occurred. Since 1998 real time flow information has been available on the internet. Now boaters can at least see when there is flow and how weird the patterns are. If you want to boat this section it is best to go with the willingness to boat at whatever flow you get. Fortunately the run is excellent over a wide flow range.
Getting there: From Fresno, take highway 168 into the foothills. Turn left on Auberry Road to th
...River Features
Smalley Cove
Campground at Kerchoff Reservoir. Picnic tables and pit toilets. No potable water. It is about a mile and three quarters down the reservoir to the dam. The scenery is nice and makes one wonder what the river canyon was like underneath the reservoir.
Kerchoff dam
There is a dock on the left, that provides an easy take out. However, this is PG&E property and the route around the left side of the dam on walkways and stairs is now fenced off. This is off limits to boaters. Boaters could avoid PG&E property by bushwacking along a large pipeline, across a small drainage to eventurally connect with a trail that leads downstream. The other option is to portage the right side (north side) of the dam. There is no trail on a steep, rocky and brushy hillside. Below the dam on the north side are broken cliffs, that will likely require rope work to descend. The hillside on the north side of the dam is reportedly private property.
Launch point
Launch wherever is convenient below the dam. The eddy current in the pool at the base of the dam will be very strong. Class 3 rapids start immediately and extend for 2/10 of a mile. Though moderate these rapids will probably wake you up and give you a good sense of what is below.
640 feet elevation approximately
Island
A long island divides the channel. Silt from the reservoir spills into the river and settles in the flat stretches of the first half of the run. The silt provides footing for trees and brush. Here the trees and brush grow completely across the river, though in a long, right to left diagonal. The river has small openings at each end of the island. The upstream opening is bigger and leads to a more gradual drop. The downstream opening is very small and has a steeper more junky drop.
Rapid
This is probably a class 3 to 3+ rapid. Trees block the view at the top, but scouting is easy from either side. There is a wide easy entrance through the trees then a couple of strong laterals slap you around. There is a hole or pour over to avoid at the bottom
Mike Walker Canyon
A private dirt road is visible on river right.
No Name
River starts bending to the south.
Grapevine Canyon & Rapid
The river is gradually bending straight south. I can't remember how big the rapid is, maybe class 3.
Southwest
River heads slightly southwest.
No Name
River heads East. Numerous rapids.
First Five
First Five should be obvious by the steeper wall on the right and the huge boulders on the left. The safest route is down the right, but it can get too junky as flows drop. Portage around the boulders on the left. There is a decent pool between here and El Limpo.
El Limpo
Big rapids start around this point. The second one is junky at lower flows and will be a portage for many boaters. The rapid has several steep drops with some constrictions in the first or second drop. There is a low water portage route against the right wall that probably also serves as a high flow sneak route.
Binocular rapid
A big long rapid. Scouting views can be had from both high on river right or left. Left is more feasible. The right side gives a more unobstructed view but requires good rock climbing skills. Depending on flow and paddler, all or part may need to be portaged. Portage on river left with great effort. Sometimes only a portion needs to be portaged and that may be accomplished at river level.
Elevation approxitmately 720 feet.
Kerchoff #1 powerhouse
The powerhouse is on river left and presents an escape route if needed. It can add another 850 to 1700 cfs into the K1 to K2 section if it is running. See the pictures and descriptions on that page. A PG&E road leads down to the powerhouse, but it is gated at the top. From the river up to the road is steep and awkward but short. From the powerhouse up to the gate on the road is almost a half mile with a couple hundred feet of elevation gain.
640 feet elevation.
Take Out
Kerchoff #2 Powerhouse
This powerhouse is underground so you will only see the outlet on the left and a road coming down to the top of this outlet. You can duck under the fence at the left side of the outlet and walk up the road to the parking area. The walking distance is about 3000 feet. Alternatively you can hike up a fisherman's trail about 30 or 40 yards to the left (upstream) of the outlet. The hiking distance is only about 700 feet, but its steep. During most seasons when Patterson Bend is runnable, Millerton Reservoir will be high and you will be paddling on this lake by the time you reach here.
Trip Reports
Log in to add a reportTelephoto view of Binocular rapid and the two following rapids.
Telephoto image taken from the take out road. Flow was fluctuating between 1000 and 1500 cfs approximately.
Binocular Rapid at 6800 cfs. Telephoto view from the take out road.
I remember joining Paul on Patterson Bend in the mid-1990's. Ours may have been one of the earliest trips after the first descent by the Holbeck and Stanley crew years prior. We attempted to portage Binocular through the boulders and poison oak on the left, wearing drysuits in the horrible heat. 'Ugh' as Paul puts it in the river description. So we ran the second two-thirds or half of the rapid, not because we wanted to, but because the alternative was heat stroke.
Richard
Timeline:
1:30 PM We arrived at Kerchoff Reservoir.
1:50 PM Floating down river towards the dam and pass bridge remains
2:20 Portaging around dam.
2:35 At base of dam getting ready to launch
3:20 1/4 to 1/3 of the way into the run.
4:06 Scouting the big Class 4 rapid
5:02 Finishing the second portage
5:46 Halfway through the Binocular portage
6:10 Finished the portage and about to run the Binocular exit.
6:54 Walking up the road from the powerhouse.
Looking towards the west down the San Joaquin valley. Millerton Reservoir, Kerkoff Reservoir (FERC P-96), Redinger Reservoir (FERC P-2017) are visible in the photo. This area of the San Joaquin is presently under study for several potential large dam and reservoir sites.
This was typical of some of the steeper drops, though a number were more congested. We successfully crashed down through this and most others. Such low water boating can be fun if you get used to it and you don't mind pinning and broaching and such. At spill flows, this becomes a delightful class 4 rapid.
Kerchoff is a small but scenic reservoir on the San Joaquin river near Auberry. It acts as a forebay for the two Kerchoff powerhouses owned by PG&E. It is a nice spot for touring kayaks, but tends to attract a few jet skis on summer weekends. The distance to the dam from convenient launching areas is about 1 3/4 miles.
Downstream view from the trail over the dam. What you see here was pretty typical of the first six miles at this low 'fish' flow; long pools seperated by rocky shallows. We were able to squeeze through all of these spots on this date.
Nice view from the pool at the base of the dam. During spill, some of these gates would be open and water would pour over the top of this dam. A stairway leads down close to this pool, but rock scrambling and a little bit of poison oak dodging is required for the final 30 or 40 feet.
I don't know what kind of rock these cliffs are made of, but there is quite a bit of it along the first 3 or 4 miles of the run. It looks like it has layers in it, so I think it is a metamorphic rock of some sort. The streambed for most of the reach is granite, but in this first section, this rock sort of alternated with the granite. Sometimes this stuff was on both sides of the river, sometimes granite was on the left and this stuff was on the right. If I find out what it is, i will update this description.
Pool just upstream of the gauging station.
This brushy island is around mile 2. The left side was obstructed at this low flow. I don't recall any problems with it at normal boating flows >1,000 cfs.
This right side of the island channel was narrow enough to put our 52 cfs to good use.
This is looking upstream from the bottom of a portage. I think it is the 3rd class 5 rapid. Fifty cfs just goes underneath the boulders, so we carried over the tops. This was the least awkward of these three portages, by a small margin.
I think this photo is just below the 3rd class 5, looking upstream. The next photo is looking downstream at, I think, the same spot. Patrick looks happy in this picture, but he knew I suckered him into this trip and that he was probably going to be late for work.
This is the prettiest part of the river with this cliff rising on the left. There are some impressive domes and cliffs on the right in this section as well. A moderate rapid waits at the end of this pool, then you arrive at Binocular Rapid.
We had a final short boulder portage around this spot in the rapid just below Binocular Rapid. At spill flows this would be a 4+ or class 5- rapid
A look at the last big section of the Patterson Bend Run. The rapid at the top is Binocular (Class V).
From the road into Squaw Leap Park, we hiked in along a dirt road to paddle the last mile or so of the Patterson Bend section of the San Joaquin River. After a mile of hiking, you come to a fence marking the start of private property. From there you can follow the fence line downhill across country to the river. Can't really recommend it. We thought we had some small spill, but we did not have time to drive to Kerchoff Reservoir. Turns out the flow was only slightly higher than base / fish flow, so we barely scraped through.
Paul and Evan climbing down this loose rock section.
What we came down to get to the river.
Evan starting this fun little rapid.
Paul taking some photos at our put-in.
Evan running the first rapid we came upon.
Paul showing us how much rapid #35 will make you smile.
Paul and the Rocks he loves.
This is the last rapid before the landscape changes and the river starts flowing into a beautiful gorge.
The gorge, where Patterson Bend ends and the Squaw Leap section begins. Paul and Evan posing next to the mossy rocks. Where you can see water seeping through the cracks.
Evan laughing out loud.
Evan having fun dropping down the 'The Shoot'.
Paul making the squeeze move.