MP: 284.51 Location: US-101 and SR 104, Jefferson Cty Reassurance shield after the SR 104 turnoff   MP: 283.1 Location: US-101 and SR 20, Discovery Bay, Jefferson Cty JCT SR 20 coming up in half a mile, the western terminus of the longest highway in the state   MP: 282.86 Location: US-101 and SR 20, … Continue reading U.S. Route 101, SR 104 to SR 20