Work on a regional trail project that would link open spaces between San Mateo and Santa Clara counties will begin on July 13 and continue through the end of October thanks to $272,711 approved by the Santa Clara County Board of Supervisors on June 7.

The Alpine Road Regional Trail Improvement Project would create a 2.3-mile regional trail for hikers, cyclists and equestrians connecting from Page Mill Road to Midpeninsula Regional Open Space District preserves, including Coal Creek and Monte Bello, along the crest of the Santa Cruz Mountains. The trail also will provide connections to the Bay Area Ridge Trail and to other trail systems within open space preserves and other park systems.

The trail is on a portion of Alpine Road between Portola Valley and Page Mill Road that has been closed to motor vehicles since 1979. Sections of the road have been impassable due to washouts, landslides and gullies since the 1990s, according to the district.

The approval by the board is the most recent in a series of actions dating back more than two decades to mitigate the impacts of development authorized by the Stanford University 2000 General Use Permit.

In early 2020, Supervisor Joe Simitian, who previously served on the state Legislature representing portions of San Mateo County, suggested using funds from the Stanford Recreation Mitigation Fund for projects in San Mateo County affected by development at Stanford. Prior to Simitian's proposal, most of the trail mitigation funds had been spent in Santa Clara County, despite the fact that development impacts occurred in both counties, he noted.

In late 2020, the supervisors voted to fund seven projects, including the Alpine Trail project, using more than $10 million in funds stemming from the 2000 Stanford University General Use Permit approval. Six of the projects are located in San Mateo County communities. The funds were made available as an in-lieu payment by Stanford after the university was unable to come to an agreement with San Mateo County regarding a trail alignment. The trail alignment had been a required mitigation for the university's more than 2 million square feet of development authorized in 2000.

Construction on Alpine Trail is expected to end in late October. A second construction phase will likely take place between June and October 2023. The Alpine Road Trail will be closed during the construction.

"The Alpine Road Trail is a really great reminder that when we work together, we can accomplish so much more. I'm pleased that our county is able to provide funding to help Midpen complete this significant trail segment. It will be enjoyed by generations of hikers, cyclists, and equestrians for a very long time," Simitian said.

"I was actually on the Board of Supervisors in 2000 when the trail mitigation requirement was approved. Little did I expect that I would be back to help ensure that the intended mitigation would be realized more than two decades later. "I'm glad to see these funds going to projects that will benefit the community for many years."

Ana María Ruiz, Midpen's general manager, said the county's support will allow the district to repurpose an abandoned segment of Alpine Road, which connects the valley floor to the Skyline corridor. The project will also allow the district to address sedimentation from the old, unpaved roadbed, which is affecting the water quality of Corte Madera Creek.