Improved Corona del Mar 5K Will Be Saturday : <i> This is the first of a series of weekly articles on running in Orange County. : </i>

Nine years ago, Jim Wood, a Newport Beach runner and real estate broker, learned that the distance between Corona del Mar and Laguna Beach was 6.2 miles--or 10 kilometers.

Either way, it’s the most popular distance in weekend road racing.

“It was a natural,” Wood said. “A 10K from Laguna to Corona del Mar. Or vice versa. What could be better?”

But when Wood, then president of the Corona del Mar Chamber of Commerce, proposed the idea to the Laguna Beach Chamber of Commerce, he was met with much opposition because of traffic and safety concerns.

So Wood settled for a shorter course through Corona del Mar.

Thus, the Corona del Mar Scenic 5K run was born.

Its seventh consecutive running will take place Saturday, beginning at the corner of Ocean Boulevard and Jasmine Avenue in Corona del Mar.

With an average of 1,300 participants a year, it’s a favorite among local racers. But it hasn’t been without its problems.

This year’s race features a new twist--separate races for men (8 a.m. start) and women (8:20 a.m.). Runners will be allowed to race in the other sex’s division, but those who do will not be eligible for awards.

The switch to separate races was implemented this year in hopes of solving the longtime problem of overcrowding along the course.

“Crowds have always been a major problem,” said Nancy Beard, co-race director with Wood.

Although the number of entrants was limited to 1,500, the narrow streets and tight corners have caused jams in the past.

A 59-year-old footbridge, though quaint, complicated matters in the early years as its width--about two runners wide--often stalled the flow.

Race officials corrected those problems by re-routing the course. The footbridge is now in the last half mile of the race.

But there have been other problems. Two years ago, the official pace moped leading the runners got too far ahead of the leaders. A trio of bicyclists intervened and, unintentionally, led the lead pack five blocks off course.

John Koningh, who led the race until he went the wrong way, said: “All I remember is realizing we were way off course, turning around, and sprinting like a mad dog to overtake (the new leader).”

Koningh, a Newport Beach chiropractor who was an All-American runner at UC Irvine, won the race. He will be one of the favorites Saturday, along with Balboa’s Derek May, 32, who is from South Africa.

In the women’s race, Harolene Walters of Mission Viejo will attempt to defend her 1987 title. Walters, 45, is a 2:47 marathoner. She was the oldest of 235 runners to qualify for the U.S. Olympic women’s marathon trials in April.

According to Beard, 1,730 runners--950 men and 780 women--had registered for the race as of Thursday afternoon. Each race is limited to 1,500 runners.

There will be pre-race aerobics, taped Bruce Springsteen music along the course, splits at every mile, a seven-story hot-air balloon, and a centipede of 30 El Toro Marines who will run and chant their way through both the men’s and women’s races.

“Things should go well this year,” Wood said. “I think it’s really going to be a success.”

Registration is $15 today (which includes a four-color T-shirt and breakfast). Registration Saturday ($20) will be available from 6:30 to 7:30 a.m.

Though their high-school running careers officially ended last Saturday at the state track and field championships, three of the county’s best prep distance runners will race Saturday at the 29th Golden West Invitational at Cal State Sacramento.

Milers Jim Geerlings of Newport Harbor High and Jim Robbins of Corona del Mar and two-miler Shanon Winkelman of Marina were invited to compete in the meet, which will feature the top seniors in the nation.

Geerlings, the Southern Section Masters champion with a 1,600-meter best of 4:09.54, and Robbins, the 3-A champion (4:10.74), will compete against six others, including Joe Devine (4:10) of Saugus and David Smith (4:09.2) of Tumwater, Wash.

Winkelman, the 4-A 3,200-meter champion who has run 9:03 three times, will compete with the season’s best field in the 3,000, including West Sacramento River City’s Reggie Williams (8:59.6 in the 3,200); Ernie Sheppard (8:56) of Piedmont, S.C., and Ian Alsen (8:59) of Granada Hills.

Race Schedule

Today:

Aztlan Sunset Indian Cross-Country 5K. 6 p.m. at Elysian Park Drive and Stadium Way, Los Angeles. Fees--$8 with shirt, $3 without. For more information, call (213) 255-1234.

Saturday:

Run for Life 5K and 10K at Centennial Park in Santa Ana. 5K starts at 7:30 a.m., 10K at 8. Fee--$12 (includes T-shirt). Also non-competitive 5K walk (8:45 a.m. start) and 1K walk (9 a.m.) available. For more information, call 526-8200.

Idyllwild 5K and 10K at Idyllwild Town Center. Fees--$10 with shirt, $6 without. For more information, call 659-4045.

Salute the Legends 5K. Restricted to runners and walkers 40 years and over. At Sun Lakes Country Club, Santa Monica. Fees--$10, $12 day of race. For more information, call (213) 588 2786.

Palos Verdes Marathon. 7 a.m. at corner of Silver Spur and Hawthorne Boulevard (behind Rolling Hills High School). For more information, call (213) 377-3419.

Sunday:

Run for Fun 5 and 10K at Woodley Park, Encino. Fees--$12 with shirt, $10 without. One-mile fun run starts at 7:45 a.m., 5K at 8, 10K at 8:30. For more information, call (818) 989-8616.