Owl Harbor Marina
Owl Harbor Marina

Sevenmile Slough · Isleton, California

Your quiet corner of the California Delta

Twenty acres on the riverfront, about an hour from the East Bay and Sacramento. Park the boat, slow down, stay a while.

20

Acres of green space on the water

#1

Best Marina in the Delta, 2 years running

1 hr

From the East Bay and Sacramento

41

Channel marker on the San Joaquin River
Why Owl Harbor?

Tenants call it “the best in the Delta.”

Tucked away amid the quiet waters of Sevenmile Slough, just off the San Joaquin River, with 20 acres of open green space, an abundance of wildlife, and views that feel never-ending. The tempo here is slower, an atmosphere that fosters relaxation, ambling walks, and the enjoyment of simple pleasures.

A beautiful riverfront setting in the California Delta, just minutes from Isleton and Rio Vista. Easy vehicle access via Delta Highways 12 and 160, a straight shot from I-80 and I-5, about an hour from the East Bay and Sacramento. By vessel, we are at channel marker 41 with no draw bridges to contend with.

20 acres of nature

Space to walk, explore, and breathe.

A quiet waterfront setting

Tucked away on Sevenmile Slough.

A community, not just a slip

Dogs, bikes, kayaks, gardens, and plenty of room to roam.

Close to everything, far from the noise

About an hour from the East Bay and Sacramento.
Life at O.H.M.

Everything you need, right on the grounds

A slower, easier pace on the water, with the amenities families enjoy.

Private, gated property

Free WiFi, electrical & water at slips, wide berths for multi-hulled vessels.

Open & covered berths

Storage units, boat and trailer storage, guest docks always available.

"Posh" restrooms

Heated showers, laundry facility, ice and refreshments on site.

Community garden

We tend a garden and hand out the produce free in the office, along with our chicken eggs in homemade OHM egg cartons. Tenants can buy a garden plot to grow whatever they choose for a one-time $10. Picnic tables and barbeques, horseshoe pits, library and video exchange too.

Pets always welcome

Well-behaved pets are part of the family here — as much or as little as you like.

Fitness gym, 24/7

Open around the clock. $20 gets you your own key and access at any time. Loaner SUPs and kayaks, loaner bicycles and helmets for exploring.
Only at O.H.M.

A few things you will not find at other marinas

Mobile pump-out boat

“Winnie the Poo”

$20 for 20 gallons. Every Thursday our groundskeepers Javier and Mario go around and do the pump-outs. Emergency mobile pump-outs are available any day other than Thursday for $50.

Campsites

Five to reserve

Five campsites are available for our tenants, including their friends, family and visitors. We can set up additional picnic tables and charcoal grills or BBQs.

Owl Harbor Marina
Three owl boxes

Wildlife

Barn owls, great horned owls and many other animals live here and we love them dearly. Three owl boxes around the property help support them.

Part of the crew

Meet Max

Max is Colin’s black lab, and he is part of the crew at Owl Harbor.

Bring the whole crew. Four legs welcome.

Berths & Rates

One rate, all year round

No seasonal pricing. Slips are priced per foot of length overall (LOA).

Open slips & end ties

$10.60

per ft. of LOA

The same rate every month of the year.

Cat / multi-hull slips

$12.75

per ft. of LOA

All year, with no maximum length.

Covered slips and side ties are listed on the full rates page.

Life at O.H.M.

Newsletters and events

Newsletter

The latest news from the harbor office and the grounds.

Links

Handy links for tenants, guests and friends of the harbor, all in one place.

Upcoming events

Follow us on Facebook or Instagram to see all our upcoming and past member events.
Find us

On the slough, off the San Joaquin

Owl Harbor
7:22 AM Nov 7, 2026
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47
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Sunrise: 6:38 AM
Sunset: 5:01 PM
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53 ° / 65 ° 0 inch 0% 2 mph 80% 1019 hPa 0 mm/h
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66 ° / 75 ° 0 inch 0% 2 mph 56% 1018 hPa 0 mm/h
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72 ° / 72 ° 0 inch 0% 3 mph 42% 1019 hPa 0 mm/h
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57 ° / 57 ° 0 inch 0% 0 mph 58% 1019 hPa 0 mm/h
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53 ° / 53 ° 0 inch 0% 8 mph 90% 1020 hPa 0 mm/h
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49 ° / 49 ° 0 inch 0% 7 mph 93% 1020 hPa 0 mm/h
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48 ° / 48 ° 0 inch 0% 8 mph 96% 1020 hPa 0 mm/h
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49 ° / 49 ° 0 inch 0% 6 mph 98% 1021 hPa 0 mm/h

Owl Harbor Marina

1550 W. Twitchell Island Road, Isleton, CA 95641. On Sevenmile Slough, just off the San Joaquin River at channel marker 41.

By road

Delta Highways 12 and 160, a straight shot from I-80 and I-5.

By water

Channel marker 41, with no draw bridges to contend with.