Thirty-five years ago, Billy Mills became the first American to win an Olympic gold medal in the 10,000 meters at the 1964 Games, a victory he achieved with a stirring, come-from-behind sprint over the last 300 meters.

"That," the 61-year-old Mills said on Friday, "was many, many, many years and about 38 pounds ago."

At 8:30 a.m. today, Mills--a former Marine who remains the only American to win the 10,000 in the Olympics--will have a far less taxing challenge. He will send a field of 21,800 Marine Corps Marathon runners on their way by firing the starting gun for the 26.2-mile ramble through Northern Virginia and the District.

Mills, also an Olympic marathoner in 1964, said he was honored to represent the Marines but felt just as much kinship with the runners, many of whom will cross the finish line hours behind the winner.

"Everything I took from the sport is displayed in the Marine Corps Marathon," Mills said.

Mills said he has become a full-fledged "slow, slow jogger" who would fit right in with the back-of-the-packers at today's race. Mills suffered severe knee, hip and ankle injuries when he was struck by a car while jogging six years ago. He is, in a sense, in the midst of a second come-from-behind sprint.

"Through the massive running boom, it gives me a chance as a 61-year-old man with a hip injury to get on out and jog," Mills said.

Mills, who lives in Sacramento, said his pace these days differs substantially from his pace as a youth, when five-minute miles were routine. He now trots along at 12 minutes per mile.

The Marine Corps Marathon features about 330 runners 60 or older (the oldest man is 82 and the oldest female entrant is 84). Forty-eight percent are running a marathon for the first time.

Today's race features a few new additions to the course. The runners will run past Union Station and the Jefferson Memorial and a dreaded stretch through the Pentagon's north parking lot has been eliminated. Runners will also find bottled water, orange slices, bagels and jelly beans available for the first time.

And, of course, they will run past Mills at the start.

"I am very humbled and very thrilled to be here for the last Marine Corps Marathon before we go into the new millennium," Mills said.