The connector from northbound U.S. Highway 101 to state Highway 1 in Marin County is closed Saturday due to a water main break, according to the California Highway Patrol.
The broken water main is located underneath the connector, which is near Mill Valley, CHP officials said around 9:40 a.m.
Work crews are currently working to repair the broken main.
The CHP did not provide an estimated time for when the connector would reopen, but anticipate the closure could last through Sunday morning, if not longer, according to officials.
Drivers are being asked to avoid the area if possible.
Drivers on northbound 101 who need to get onto Highway 1 can exit at Seminary Drive and reentering southbound Highway 101 to access Highway 1 connector, CHP officials said.