A wildfire in the mountains above Santa Anita in Arcadia, Calif. has significantly curtailed visibility and affected training at the racetrack in recent days.The fire, which began on Sept. 6, is burning in mountains to the northeast of the racetrack and covered more than 23,800 acres by early Friday, according to fire officials. The smoke was so severe that sunlight was noticeably reduced in Southern California, though not as much as in Northern California.Most of the stables that spent the summer at Del Mar relocated to Santa Anita in recent days. The track does not open its autumn meeting until Sept. 19. Originally, Santa Anita was awarded racing days for this weekend, but opted to create a 12-day gap from the end of the Del Mar meeting this past Monday to Sept. 19.It is doubtful Santa Anita would have raced this weekend because of the poor air quality. Golden Gate Fields in Northern California canceled its Friday program because of poor conditions.“Thursday, the smoke was really bad,” trainer Kristin Mulhall said from Santa Anita on Friday. “Today, it’s horrific.”Many trainers kept horses in the stable or gave them minimal racetrack exercise. There were two workouts on Thursday and 11 on Friday.“I tack-walked some and jogged some,” trainer Phil D’Amato said. “I’m not doing much with them.”D’Amato and his family live north of Santa Anita toward the mountains above the racetrack. There were a few anxious days in their neighborhood earlier this week.“It got pretty close to us a couple of days ago,” D’Amato said of the fire. “It looks like everything is under control.”Evacuation warnings were issued for several cities near Santa Anita, including Arcadia, Bradbury, Monrovia, and Sierra Madre where many people involved in Southern California racing reside. An evacuation warning is issued prior to an evacuation order, when time allows.Fire crews were using aircraft and helicopters to drop fire retardant and water on the fire in remote canyons on Thursday and Friday. Air quality is expected to be poor through Saturday, fire officials said.