hitchhiking reached its peak around 1971, especially the summer in Big Sur, which became a mecca for hitchhikers who were looking for a ride north or south through California or just to backpack in the Big Sur backcountry.

Three young women hitchhiking on Highway 1 in Big Sur on September 5, 1971.

http://heraldphotos.blogspot.com/2013/07/hitchhiking-in-big-sur-1971.html