It basically completes the excavation work on the first of two tunnels, which will steer traffic away from Devil's Slide between Pacifica and Half Moon Bay.
Chunks of sprayed concrete fell away from the north portal as an Austrian tunneling machine chewed through from the other side.
Crews have been working for three years, 24 hours a day, 7 days a week, at a rate of about 10 feet a day to reach this point. The people of San Mateo County came to watch the fulfillment of a decades-long battle.
"I didn't know that this was going to happen when we started fighting the original plans for a bypass for Devil's Slide in 1972," says community tunnel advocate Lennie Roberts.
Highway 1 at Devil's Slide has never been a reliable route along the coast, closing routinely because of landslides and rockslides.
Coastal economies and families suffered with the tunnel, Pacifica will no longer have to be a cul-de-sac where cars turn around once a year in bad weather.
Roberts was one of the many locals who fought for the tunnel and against the plan for a freeway across San Pedro Mountain.
"It was originally planned to go, a freeway down the coast, from San Francisco all the way to San Luis Obispo -- Highway 1. That was a 1960's grandiose plan," says Roberts.
"The old Highway 1 will allow bike riders and pedestrians to have a quiet vista from which to view the Pacific. What a tremendous gift this is to future generations," says Jackie Speier, D-San Mateo.
Each of the two tunnels are just over 4,000 feet long. The $300 million price tag is being paid for entirely with federal emergency highway relief funds.
It will be two more years before both tunnels are completed and open to traffic.