Once each year, a 26.2-mile stretch of Highway 1 along California's majestic central coastline closes due to heavy traffic-six hours of bumper-to-bumper sneakers, worn by 4,500 runners tackling the Big Sur International Marathon. The race meets for its 21st time on Sunday, April 30, and registration has been closed since late January for what many call the most beautiful marathon in the world.

To call the undulating, winding marathon course --from the redwoods in Pfeiffer Big Sur State Park to the Monterey Peninsula's rocky, sweeping Pacific coastline "scenic," would be like describing Bill Gates as "well off." In late April, the area's rolling hills wear a lush green carpet instead of their usual dry grass and are punctuated by bright swaths of wildflowers. Waves crash below as runners trace "the Edge of the Western World" past Point Sur Lighthouse and the occasional cow or horse. The view-particularly from the bridges runners cross-can be breathtaking, although some Big Sur veterans claim the surrounding beauty, as if by magic, actually helps them find the extra gasp needed to make it across the finish line against a whipping wind.

Lest anyone forget they're in California, belly dancers and other eccentric performers line the route. Taiko drummers (historically used to inspire Japanese troops) beat at the start of Hurricane Point, a two-mile climb to 520 feet-the race's most challenging section; on the other side, a tuxedoed pianist plays a Yamaha grand as runners near Bixby Bridge.

Another 2,800 walkers, runners and in-betweeners partake in a relay race and four shorter, slower events, including a 5K run to Point Lobos (the only activity still open.

All these events help raise money for four official charity teams JUST RUN youth program and local chapters of Boys & Girls Clubs, United Way and Habitat for Humanity, plus other local groups.

If you don't run, you can join the cheering crowds along the last five miles. If you're really inspired, registration for the Big Sur Half Marathon in October opens April 1, and free training clinics for next year's big race start in November.

Photo: Big Sur International Marathon