A Garfield County road supervisor testified Monday that silicone was found in the engines of four bulldozers vandalized in the wake of a ruling permitting roadwork on Utah's controversial Burr Trail.

The testimony came in the first day of a preliminary hearing in 6th Circuit Court for Grant Smith Johnson, 31, who is accused of sabotaging the machinery on Dec. 3, 1987.Johnson, who has lived in the Deer Creek environmental enclave beside the Burr Trail near Boulder, is charged with four counts of criminal mischief, a third-degree felony. He also faces felony charges of growing marijuana, possessing hallucinogenic mushrooms and possessing marijuana with intent to distribute, among other charges.

Garfield County won a lengthy court battle with environmentalists over plans to upgrade a 27-mile stretch of the dirt road, which meanders over 66 miles of some of southern Utah's most spectacular desert terrain.

Road supervisor Ron Greenhalgh testified that he checked the county's bulldozer on Dec. 4 and found it had "seized up" and would only run for a few minutes at a time, just like three other privately owned bulldozers.

He said the equipment was removed from the site and the engines sent to a repair company in Salt Lake City, where a grainy substance later identified as silicone was found in the oil pans.

Defense attorney Ron Yengich objected several times to the testimony, saying Greenhalgh couldn't say exactly what work was done "by looking at an invoice," but Judge David Mower overruled his objections.

Mower also refused Yengich's request to sever the mischief and drug charges, but he did say that the charges would be separated if he decided to bind Johnson over for trial in district court.

Testimony was to resume Monday afternoon, and attorneys said the hearing could last through Thursday. Johnson is free on bail $250,000 bail.