Environmental groups are suing the U.S. Forest Service over a plan that lets hunters drive off designated roads to retrieve elk and bison.
Each of the ranger districts in the Kaibab National Forest allow hunters to venture a mile off the road in their vehicles to pick up big game during hunting season. Forest officials encourage hunters to use the most direct route that would limit disturbance.
The environmental groups say the off-road travel harms wildlife habitat and cultural resources. They also argue that it can spread invasive and noxious weeds.
They asked a judge in a lawsuit filed this week in U.S. District Court in Arizona to force forest officials to do more rigorous environmental reviews.
Kaibab forest spokeswoman Jackie Banks declined comment, citing pending litigation.