Sign ups are now available for the inaugural RockWater run from Big Bear Lake to Newport Beach.
A brainchild of the Surfrider Foundation Newport Beach Chapter, the race kicks off at midnight following the spring equinox on March 21 and follows the entire distance of the Santa Ana Watershed along its course from the mountains to the sands of Orange County.
The 100-mile relay lets runners choose a distance that is comfortable for them and allows substitutions at any point along the course, organizers said.