Link to the Routes. The 35 Mile run "North" out of Cambria is I believe the Sunday ride. Where they come up with 5 miles of gravel is a bit strange, as this is all North on PCH. Maybe the little run to the Lighthouse in and out.
https://www.eroicacalifornia.com/routes
Then they added another route that is "open to other bikes" vs Vintage only. This is Saturday also:
Want to experience the most challenging and spectacular gravel roads of the Central Coast of California? Join NOVA Eroica California! A group ride event with fun, timed segments open only to ROAD and GRAVEL bicycles. Starting separately from the Eroica classic event, NOVA Eroica take a step beyond vintage to celebrate the beauty of fatigue and the thrill of conquest also on modern bikes.