Chilly temperatures and a rollover that injured a Sandy driver have characterized weeklong trail runs in the 22nd annual Easter Jeep Safari in the Moab area, authorities say.

The recreational vehicle event began last Sunday with runs on 18 designated back-country trails. "Cliff Hanger Trail" leader Ron Brewer said vehicles have numbered as high as 60 on any one run so far."It seems like the hardest trails have had the biggest numbers," he said.

The trail runs precede the main events this weekend, including the traditional Jeep Safari and Boy Scout Barbecue on Saturday. Sunday's events include a nondenominational Easter service scheduled for sunrise in Arches National Park and the Sand Hill Climb competition for beefed-up four-wheel drives.

Brewer said 247 vehicles were pre-registered for the Jeep Safari as of Thursday evening, keeping the contest in line with previous participation figures despite unseasonably cold weather the past few days.

Participation in the off-road event, organized by the Red Rock 4-Wheelers Club, has grown steadily every year, drawing in 1987 a record 700 registered vehicles. Organizers estimate an additional 200 vehicles join in without registering.

Icy temperatures, cloudy skies and scattered snowfall greeted recreationists the past two days. Bonnie Midlam, a local weather watcher, said temperatures ranged from 79 to 21 degrees over the past five days.

Grand County deputy sheriffs planned to resume efforts Friday to retrieve a Jeep that rolled on Lion's Back Ridge east of town Thursday afternoon.

Deputy Kent Green said a Colorado driver escaped injury after hitting a bump that flipped the Jeep on its side. Rescuers righted the vehicle, only to watch it roll over on the other side and block the middle of the trail.

Earlier, a Sandy man suffered a broken jaw when his vehicle rolled on U-128, Green said.

The driver apparently lost control of his pickup truck on a sharp curve during a brief rainstorm that turned to snow Wednesday night. The truck went up an embankment and required two wreckers to set it upright, he said.