Diablo Road Trail: 2026 Progress and Open Magee Trails

The crews running alternating one-way traffic between Fairway Drive and Alameda Diablo are building the final 0.9 miles of a paved trail. The trails it connects to are already open. East Bay Regional Park District trails at Magee Preserve opened to the public in June 2025, and Save Mount Diablo announced two more in August 2026, including one built to tie into the new Diablo Road bike path.

So the delay on Diablo Road is for a connector. Its destination has been open for more than a year.

Where the walls stand this week

The Town of Danville's latest update, dated Friday, September 25, 2026, says the three retaining walls along Green Valley Creek are substantially complete. That was the biggest job on the project. Crews drilled 72 piles, the vertical beams that hold the concrete wall panels in place, 30 to 40 feet into the ground. Then they set panels across three wall sections totaling 410 linear feet. On September 4, about 245 of those feet were in place. By September 11 it was about 320 feet, with all 72 piles installed.

The walls also protect the road itself. According to the Town, they strengthen Diablo Road along the creek and "significantly" reduce the risk of erosion and the need for future road closures.

Next, crews will install smaller walls along the trail east of the large culvert near Alameda Diablo, along with drainage work. That prepares the ground for the trail base and asphalt paving. The daily flagging start moved from 7:00 a.m. to 8:30 a.m. as of August 31 to ease morning commute traffic.

On timing, the Town's August 3 notice said traffic control on this phase would continue "through approximately October 15." It also said the full project should be finished by December 2026. The September 25 update doesn't restate either date. When the project broke ground in October 2025, the Town said work would pause "from November through March" to avoid the rainy season. A June 2026 notice expected wall and trail construction to wrap up in October. Taken together, December depends on paving getting done before the weather turns. Until the Town posts a new date, December is a forecast.

The full route, west to east

Danville describes the finished trail as an 8-foot-wide paved Class 1 multi-use path along the south shoulder of Diablo Road, connecting Green Valley Road and Blackhawk Road. It has three pieces:

1. The Barbara Hale Trail. This is the existing 0.5-mile segment, also called the Diablo Road Trail.
2. The new segment. This is the 0.9 miles under construction now, running from Fairway Drive to about 400 feet west of Avenida Nueva.
3. The Magee Preserve path. This 0.7-mile trail was built as part of the Magee Preserve development.

Those pieces add up to 2.1 miles. The trail first appeared in the Town's 1989 Townwide Trails Master Plan. At the October 2025 groundbreaking, Danville Mayor Renee Morgan said, "Over 36 years ago, we were standing here, envisioning this trail." The budget is $5.2 million. Of that, $4.7 million comes from the Contra Costa Transportation Authority's Measure J transportation sales tax.

Magee Preserve is already open

The east end of the route runs into Magee Preserve. Most of that 410-acre property became public land after a long process. The Danville Town Council approved the project unanimously in 2019. It was then challenged by referendum, and in 2020 Danville voters passed Measure Y, which permanently protected 93 percent of the property. Today that means 381 acres of publicly accessible open space, with 69 homes planned on 29 acres south of Blackhawk Road.

Public access came in two stages. On June 24, 2025, East Bay Regional Park District held a ribbon-cutting that made more than 3.5 miles of Magee Preserve trails officially public. Those trails connect to Sycamore Valley Open Space Regional Preserve. In August 2026, Save Mount Diablo opened two trails of its own at Magee Preserve, adding more than two miles.

• Art Bonwell Trail honors one of Save Mount Diablo's co-founders, who was an avid cyclist. Land Programs Director Sean Burke said naming this trail for him, "where it parallels and ties into the new Diablo Road bike trail," was "a no-brainer."
• Do'-yum'-bel'-le Vista Trail uses the Bay Miwok name for Mount Diablo. Burke described how the name was chosen:

The name "was decided upon after conversing with many local tribes in the area to commemorate the Bay Miwok name for Mount Diablo, as this particular trail has great views of the mountain that is the center of creation for the Bay Miwok and exists on Bay Miwok territory."

Many people helped build the trails. Executive Director Ted Clement thanked Davidon Homes for donating the trail easement. He also thanked Dave Hammond and the Trail Dogs volunteers, East Bay Regional Park District, and the Town of Danville. Students from Athenian High School helped build trails in the preserve. Clement said these two trails bring Save Mount Diablo's total to almost 10 miles of trails built and opened in the last few years.

Until the Diablo Road segment opens, you can get into the connected Sycamore Valley preserve from its official entrances. The park district lists two parking areas, the Holbrook Drive and Sherburne Hills Road staging areas. It also lists walk-in entrances at Sunhaven Road, Northview Court, Tuscany Way, Woodside Court, and Country Hills Court. Parking is free, and the preserve is open 5 a.m. to 10 p.m.

Where it meets the state park

The Town calls this project "the final connection between the Barbara Hale Trail and Mount Diablo State Park." That's accurate in a regional-planning sense, since the route widens access toward the mountain. None of the Town or park pages we reviewed shows a continuous path from the east end of the trail to a state park gate. The finished segment links Diablo Road to Magee Preserve and Sycamore Valley.

The documented trail into the park from Danville is a separate route. East Bay Regional Park District's five-mile Las Trampas-to-Mt. Diablo Regional Trail starts at Hap Magee Ranch Park, passes under I-680 and over Stone Valley Road, and enters Mount Diablo State Park at Macedo Ranch Gate. At the Macedo Ranch Staging Area it meets the Briones-to-Mt. Diablo and Green Valley regional trails. Bikes are allowed on only part of the route. Today, that's the route to take if you want to walk into the park from town.

On the mountain this month

Today, October 4, the Mount Diablo Challenge closes North Gate, South Gate, and Summit Roads to cars from 8 a.m. to 2 p.m. Macedo Ranch and Mitchell Canyon stay open, and so do the trails and fire roads. Here's what else is on the calendar:

• Oct. 10: Astronomy Night, listed on the Mount Diablo State Park page.
• Oct. 14: Wonder Hike, on the same park listing.
• Oct. 24: Save Mount Diablo's Borges Ranch Fall Hike, 9 a.m. to noon. Afterward, hikers can visit the old ranch buildings and farm animals.
• Oct. 25: Halloween Hike on Devil Mountain.
• Dec. 7: Save Mount Diablo's annual Beacon lighting at the CSU East Bay Concord Campus. A USS Arizona reception and exhibit starts at 3 p.m., the ceremony at 3:45 p.m., and the lighting at 5 p.m.

The Summit Visitor Center is open daily from 10 a.m. to 4 p.m., but its elevator is out of service until further notice. Save Mount Diablo's free Discover Diablo outings open registration one month before each date.

On Diablo Road, the next step in the Town's sequence is the trail base and asphalt paving, after the smaller walls east of the culvert near Alameda Diablo are in.

Once the trail is paved, Diablo Road will have a continuous path from Green Valley Road into Magee Preserve. Changes like that are part of how Russ Darby and our team understand homes in this corridor. If you'd like a current read on what your Diablo-area home is worth, Request a Home Valuation and we'll put our local knowledge to work for you.