By Devin Fehely

SAN MATEO COUNTY (KPIX 5) — Caltrans is predicting it could be two weeks before the agency is able to reopen a stretch of State Highway 35 (Skyline Boulevard) near the intersection with Page Mill Road in unincorporated San Mateo County.

Caltrans says a massive sinkhole has undermined the road and clawed out a large section of dirt, debris and asphalt.

“The sinkhole has done nothing but get larger. We’re finally containing it a bit. But that’s only because it stopped raining,” said Caltrans Spokesperson Jeff Weiss.

Weiss says drivers first noticed cracks in the road during Sunday’s storm and the situation quickly got worse from there.

“It didn’t take long for a sinkhole to develop. And it grew very rapidly. And we immediately closed the road,” Weiss said.

The extensive damage to Highway 35 that Caltrans crews are working on. (CBS)

State Highway 35 is a much-traveled mountain road in the hills above Palo Alto and Cupertino in unincorporated San Mateo County.

“It’s so inconvenient because the roads are blocked. And there’s not many others options that you can take around this area,” said driver Jennifer Arevall.

Arevall says the closure will likely mean long and inconvenient detours for drivers who depend on Highway 35.

Caltrans says the plan is to build a temporary retaining wall right down the middle of the damaged road. Once that work is complete, a Caltrans spokesperson says one traffic lane will reopen.

It’s estimated that permanent repairs will likely take several months to plan and build.