Environmentalists believe the 10th Circuit Court of Appeals in Denver may have upset rural counties' applecart on Utah's dusty dirt roads.

The appellate court has upheld a strict standard for what constitutes a highway under a 19th-century mining law known as RS2477. And that standard may supersede what's outlined in an agreement signed recently between Gov. Mike Leavitt and Interior Secretary Gale Norton that would speed up the process of turning over rural roads to state ownership.

"As a result of the 10th Circuit's decision, the law of the land in Utah is that faint hiking trails, two-tracks and abandoned prospecting trails cannot be raised from the dead as a weapon against wilderness protection for Utah's spectacular canyon country," said Heidi McIntosh, conservation director of Southern Utah Wilderness Alliance.

That means it will be harder for local counties to take ownership of a disputed road on federal land.

In a new ruling, the appeals court upheld U.S. District Judge Tena Campbell's decision that counties can't simply claim ownership on long-abandoned trails that do not access any particular destination.

That standard may not conflict with the agreement between Leavitt and Norton. Leavitt has said the agreement only applies to well-traveled roads that are part of the county's transportation system. And no roads in parks, refuges and wilderness would be considered. If that's indeed the case, the roads that Leavitt seeks might meet the Campbell standard.

The governor could not be reached for comment Tuesday.

One caveat to the Leavitt-Norton deal is that counties would be free to pursue their own claims on roads that may not meet the new federal court standard. Many of those roads are jeep trails that crisscross public lands. And under the Leavitt and Norton deal, if a vehicle can drive on it, then it's a valid highway.

"If you focus just on the use alone, Leavitt and Norton opened up the door to any two-track that you can drive a Subaru is a highway," McIntosh said.

Not under Campbell's definition.

Campbell's ruling said at least two criteria must be met to be a valid RS2477 claim: It had to be constructed, not created simply by passage of vehicles; and it had to have an identifiable destination, not simply vanish in the desert.

"This decision criteria set forth in the (Leavitt-Norton agreement) is much looser, much fuzzier than what Campbell said," McIntosh added.

But the issue dates back to 1996.