By ROBERT WELLER

DENVER – Even as ski resorts crack down on reckless skiing and snowboarding by introducing slow zones and speed patrols, prosecutors are putting a ski racer on trial for manslaughter.

Nathan Hall, then 18, is charged with felony manslaughter in the death of a skier he hit while bouncing down a bumpy run at Vail Mountain after finishing his shift as a lift operator in April 1997.

Buck Allen, a Vail municipal judge and expert skier, saw Hall flash by, “sitting way back on his skis” and unable to stop. Hall smashed into Alan Cobb, killing the 33-year-old Denver skier almost instantly.

The trial, which had been scheduled to start Monday, has been postponed until Nov. 8.

District Attorney Mike Goodbee said he asked District Judge David Lass to disallow testimony from an expert who had just been added to the defense’s list of witnesses last week, arguing Hall’s attorneys had not fully complied with requests for information.

The judge on Saturday declined to strike the witness, but said he would postpone the trial. He set the new date during a brief hearing Monday morning.

Two Eagle County courts dismissed the charges against Hall, ruling that “a reasonable person” would not have expected skiing too fast to cause another person’s death.

With law enforcement complaining this decision gave reckless skiers carte blanche, the Colorado Supreme Court granted the prosecutor’s appeal and ordered Hall tried. The Chico, Calif., college student could face up to six years imprisonment.

“What better state than Colorado to decide this issue? And what better county than Eagle?” Goodbee said. Goodbee’s jurisdiction includes the Vail and Beaver Creek resorts; most residents ski or snowboard and many work at resorts.

In the three years since Cobb’s death, major Colorado resorts have stepped up their enforcement of ski safety rules. Vail seized a record number of lift tickets in 1998. And to further prevent injuries, Vail, Breckenridge and Keystone, the nation’s busiest resorts, created speed patrols in 1999.

Goodbee and Hall’s lawyer, Brett Heckman, were under court gag orders, limiting what they could say, but Heckman appeared likely to argue that times have changed, and that his client’s conduct wasn’t unusual in 1997.

Goodbee agreed the climate has changed. “If the slopes are safer now, then Alan Cobb’s death wasn’t in vain,” he said.