Blythe Miller, the only woman to win the National Steeplechase Association jockey championship, announced her retirement after 15 years in the saddle, 202 steeplechase victories, and more than $5 million in purse earnings.Miller, 34, walks away from the sport but made her decision based partly on two races last summer. She sustained back-to-back concussions in one week at Saratoga, and did not ride the remainder of the season. The injuries have long since healed, but Miller had considered retirement at the start of the season and finalized her decision this winter.The Pennsylvania resident leaves with a gaudy resume that includes two NSA championships (1994 and 1995), the seventh spot on the all-time list of career wins, the unofficial purse earnings record of $5,177,363 (records aren't available prior to 1977), and a host of talented mounts.Miller, daughter of trainer Bruce Miller, rode five-time American champion and career earnings leader Lonesome Glory, two-time champion Flat Top, champion All Gong, NSA grade I winners It's A Giggle, Campanile, Victorian Hill and Uptown Swell. In addition to her father, she rode for Hall of Fame trainer Jonathan Sheppard, champion trainer Janet Elliot, and dozens of others.Retirement won't come easily to Miller, known as one of the fiercest competitors on the circuit. She will consider training, but for now is content to be an exercise rider at California flat tracks."I'm still adjusting to (to retirement)," she said. "I will miss it, but I was going to miss it no matter how I went out. I'm fortunate with the career that I did have, and I'm glad to walk away fine."Like flat racing, steeplechase racing is one of the rare sports where men and women compete, and Miller had little trouble earning the respect of her peers."The first year or two, they treated me differently and I don't know if it was because I was a girl, or because I was young, or because I was amateur, but I'd say it was because I was a girl," she said. "You had to earn your respect but I did that. Looking back on it, I can see I did that because after a while, they didn't treat me like I was any different."Miller, who won two jump races in England and also scored victories on the flat (including one at Saratoga), didn't give up on her career. The time had simply come. American jump jockeys who last more than 10 years are rare. It's a young person's game. Of the 12 champions since 1990, only four (Dave Bentley, Gus Brown, Arch Kingsley, and Blythe's brother Chip Miller) are still active.