The SDC Campus Is Stuck Until 2027. The Land Around It Is Becoming Part of Jack London Park.

On the east side of Eldridge, people park along Harney Road and walk past a metal gate to reach Sunrise Road. That's how State Parks tells visitors to get onto the Sonoma Developmental Center Open Space, and it's free. The September 2026 SDC Open Space newsletter, posted on the State Parks site, says it plainly: "Park does not charge for entry."

Up Arnold Drive, the gate at London Ranch Road charges $15 per vehicle to enter Jack London State Historic Park. On paper, those two pieces of ground are now heading toward being one park.

What the October 14 filing set in motion

According to the SDC Open Space news page, State Parks' Bay Area District and Jack London Park Partners filed paperwork in September to amend Jack London State Historic Park's General Plan to include 765 acres of SDC open space. The amendment would take the park's total past 2,200 acres. Jack London Park Partners puts the existing park at 1,565 acres, so the SDC land adds roughly half again to what Glen Ellen already thinks of as Jack London.

The day-to-day management stays split. Jack London Park Partners keeps running Jack London SHP, and State Parks staff keep running the 765 SDC acres. State Parks' main SDC Open Space page says that "initially, the property and how everyone accesses it will not change," and that the land "will eventually be incorporated into Jack London State Historic Park through a public General Plan process." That public process is the next step. State Parks hasn't said whether entry fees, dog rules or hours will stay as they are once the land is formally part of Jack London, and it hasn't said they will change either.

The acreage figures have moved over time. The January 2024 transfer announcement described about 650 acres, the park page says about 750, and the October update uses 765. The 765 figure matches State Parks' description of the SDC property as about 180 acres of developed campus plus 765 acres of natural areas. Not everything on the property is part of the deal. Both lakes stay with the local water district, and CAL FIRE receives part of the southeast corner for a future facility.

Three neighboring parks, three different front doors

For anyone who walks this stretch of the valley regularly, the practical differences come down to who runs each piece and what it costs to get in.

The SDC land sits between the other two, and State Parks describes it as the link from Jack London to the county park, part of a regional wildlife corridor that runs from the Marin coast to Blue Ridge and Lake Berryessa. In late May and early June, State Parks and CAL FIRE graded the Suttonfield Lake fire roads between Sunrise Road, Sonoma Valley Regional Park and the CAL FIRE station. That work was meant to improve patrol, maintenance and resource-management access through the summer and fall, and it didn't open a new signed trail. The Sonoma Valley Sun's July profile of the regional park describes the paved Valley of the Moon Trail as about 1.2 miles long, with Woodland Star and Cougar trails making loops on the hillside.

The dog rule differs on each side of the boundary

Dog owners will feel the merger more than anyone, because the two parks already have different rules. On SDC Open Space, dogs must be on a leash no longer than six feet and may only use paved roads. Every trail is closed to them except to service animals. At Jack London, the park's own visitor page calls the property a wildlife sanctuary and allows dogs in designated historic areas, including the Beauty Ranch area and the trail to the Wolf House ruins, and on no other trail.

That's why the paved Sunrise/Baker loop is the main dog walk on the SDC side. State Parks describes it as a flat loop of 45 to 50 minutes on the east edge of the property. It circles a seasonal wetland and passes the old farm, horse corral, dairy, maintenance buildings, sewage treatment plant and soccer field. Those were the pieces that once made SDC a largely self-sustaining community. State Parks launched its B.A.R.K. Ranger program on the property on August 22. Dogs whose owners learned the leash and wildlife rules at a pop-up tent left with a wooden badge and a Polaroid, and five dogs were inducted on the first day.

What's on the calendar through the end of November

The SDC side is the busier of the two parks right now, and much of its programming is free.

• Prescribed burn, East Suttonfield, starting as early as Tuesday, Oct. 27. State Parks scheduled burns on up to 29 acres of grassy oak woodland east of Lake Suttonfield, in burn units 2 and 3, starting Oct. 27 or later in the week if conditions allow. Smoke may be visible from 9 a.m. to 6 p.m. on burn days and for up to two days after ignition. Nearby trails may close temporarily. State Parks asks people not to call 911 about this smoke and posts updates on the Watch Duty app.
• Halloween Costume B.A.R.K. Ranger Pop-Up, Saturday, Oct. 31, 9 a.m. to noon. Look for the State Parks tent near Sunrise and Baker on the east side, with Halloween-themed prizes for dogs in costume. Park along Harney Road and walk past the eastern metal gate.
• "Hunting for the Snark Illustrations," Friday, Nov. 6, 11 a.m. to 12:30 p.m., Jack London SHP. This Jack London Society speaker program costs $15, and the fee covers park entry.
• Author's Afternoon with Marlo Faulkner, Sunday, Nov. 15, 2 to 3:30 p.m., Jack London SHP. The program is free with a reservation, and the $15 vehicle fee still applies.
• Jack London Memorial, Sunday, Nov. 22, 10:30 a.m. Free, with the vehicle fee.
• SDC Open Space Thanksgiving Guided Hike, Saturday, Nov. 28. It's on the Jack London park page, and State Parks hasn't posted a start time yet. Recent State Parks hikes around Lake Suttonfield have met at Harney and Railroad in Eldridge. They covered about 2.5 miles of unpaved trail, easy to moderate, in about an hour and a half.

If you're going on Thanksgiving Day itself, Jack London's park and museum are both open.

The staff building out the SDC side

Most of the activity on the SDC land comes from a small State Parks team. In May, the Bay Area District hired State Park Interpreter Carmen Vanni and Associate State Archaeologist Sally Gaston for SDC Open Space. Gaston is surveying and cataloging the property's cultural resources, and that inventory will become the basis for new signs, kiosks and programs. Five interpretive panels for the Cannabis Watershed Protection Program are in the works, and staff confirmed where they'll go during a site visit on September 11.

The September 12 BioBlitz around Lake Suttonfield recorded 361 observations of 152 species from 14 observers over a week. The first one, in 2024, logged more than 140 observations and 75 species, so this year's species count was about double. The results are on iNaturalist. On October 16, State Parks posted an SDC Open Space Visitor Survey, and the answers will help decide what interpretive programs the property gets next. The same day, the district set up a public email address, [email protected], for accessibility questions.

Camp Via, the former SDC summer camp on Sonoma Mountain, transferred to State Parks in June 2024 for hiking, biking and horseback riding, although the main SDC page still describes the transfer as in progress.

Meanwhile, on the core campus

The 180-acre campus of buildings visible from Arnold Drive is moving much more slowly. Sonoma News reported on August 31 that Permit Sonoma no longer expects to release the draft environmental impact report for the SDC Specific Plan and Eldridge Renewal's proposal in 2026. Director Scott Orr now estimates spring 2027. The proposal under review calls for 990 homes, 130,000 square feet of commercial space and a 150-room hotel, and the state Department of General Services still owns the campus. A writ hearing in Sonoma Valley Next 100's lawsuit against the department is also scheduled for November, according to the Sonoma Valley Sun.

At Mark Stornetta, we follow what happens to the open land around Glen Ellen as closely as we follow the houses, because protected acreage, trail links and boundaries shape what the surrounding properties are and how they're used. If you own property near Eldridge or Jack London and want to understand how changes to the SDC land relate to it, we're glad to talk it through privately. Request a Confidential Consultation.