CEDAR CITY, Utah (AP) _ One of the teen-age boys who fled a camp for troubled youth turned himself in Monday after trudging 30 miles across the frosty Utah desert, two days after some boys beat a counselor and tied up another.

Search crews with bloodhounds and helicopters continued to scour southern Utah for six other boys who fled Saturday.

Authorities were concerned about the boys' ability to survive in the rugged wilderness after two nights in the bitter cold. The boys, between the ages of 14 and 16, had some survival gear, wool coats, blankets and a two-way radio, but only one-day packs of food.

``We're absolutely worried about them,'' said Iron County Sheriff David ``Dude'' Benson. ``They've done some stupid things, but they're just kids.''

An eighth boy in the group turned himself in Saturday after he became ill and was abandoned by the others. He was charged with felony aggravated assault, simple assault and theft.

``The boys are not outfitted for extended periods in this type of weather and this type of terrain,'' said Steve Peterson, co-founder of Red Cliff Ascent Inc., which teaches wilderness survival skills to troubled youth.

Benson said the teens beat 23-year-old counselor Kirk Stock with sticks on Saturday, tried to break his legs and then bound him with duct tape. The boys allegedly threatened 22-year-old counselor Sunshine Fuller, tied her to a tree and fled. They escaped near Cedar City, 220 miles south of Salt Lake City.

The boy who turned himself in Monday wasn't identified. He showed up at a hog farm in rural Beaver County and was taken to a command post near Lund. His condition wasn't disclosed, and Benson said he hasn't been charged with any crime.

He was brought out with the searchers to show them where he last saw the rest of the group. Authorities were trying to determine if he was directly involved in the alleged assaults.

One of the camp's founders said authorities told him they had found fresh tracks within 10 miles of the hog farm, indicating progress in the search of the rocky backcountry.

``They think they're closing in the on rest of the kids,'' said Scott Peterson, Steve's brother and Red Cliffs co-founder.

The boys, who were sent to the camp by their parents, came from Silverton, Ore.; Plainfield, Ill.; Austin, Texas; Wynnewood, Pa.; Kildeer, Ill.; and Greenwich, Conn., and two unspecified towns in California and New York, according to Utah officials.

On Saturday, their first night of freedom, temperatures fell to 6 degrees. Sunday night, the low was 17. Afternoon temperatures on Monday approached the 60s under sunny skies.

Benson said the alleged attack was not the first time Red Cliffs has had runaways during its camping trips. In previous cases, he said Red Cliffs officials captured the runaways.

Scott Peterson said the program has treated 1,500 children in seven years. He said many are sent by parents or courts but until now the company has never had a group of children overtake the staff.

``We teach our people the best we can, but it's not a perfect science,'' Peterson said.