The search for the suspect in last weekend’s Kentucky highway shooting has taken authorities into a massive, dense forest that’s been compared to a jungle in the southeastern part of the state. The manhunt for Joseph Couch, 32, has been going on since Saturday, when authorities say he shot and wounded five people who were traveling on Interstate 75.

The shooting happened near London, Kentucky, a city of about 8,000 outside Daniel Boone National Forest, which has “some of the most rugged terrain west of the Appalachian Mountains,” according to the U.S. Forest Service. The terrain includes “steep forested slopes, sandstone cliffs and narrow ravines,” according to the agency.

“It is like a jungle,” Kentucky State Police Master Trooper Scottie Pennington told reporters Monday, “and we have cliff beds, we have sinkholes, we have caves, we had culverts that go under the interstate. We have creeks and rivers and the dense brush. I mean, it’s not something I can just take my dog for a natural walk through.”

The forest spans more than 2.1 million acres, including state and privately owned land, according to the Forest Service. The agency manages over 707,000 acres of the area and Pennington said it’s been assisting with the search.

In addition to the Forest Service, multiple law enforcement agencies are also helping with the search effort, including the FBI, the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, local police forces, sheriff’s departments and the U.S. Marshals Service, Pennington said. The U.S. Fish and Wildlife Service has also provided boats to navigate rivers in the forest.

Pennington posted a video to social media Tuesday showing the dense brush that search teams are combing through with the help of dogs.

He noted that while investigators are looking for the suspect, they’re also gathering anything he may have left behind.

“Our ground teams, you know, they’re like snails, they’re going very slowly to make sure they don’t leave anything unturned,” he said. “It might be a tree that’s knocked over, and it doesn’t look right the way it’s knocked over or something, a piece of trash on the ground, a candy bar wrapper, anything like that. I mean, we have to collect those because that might be part of the evidence.”

Meanwhile, helicopters and drones have been searching from the air, with the helicopters able to track heat sources on the ground.

As difficult as the area has been to search, Pennington said he hopes a lack of resources in the forest helps drive the suspect out of hiding.

“I hope he doesn’t have water, I hope he doesn’t have food, and I hope he’s just, he’s wore out, and eventually he’ll walk out of them woods,” he said.

Authorities are also looking for signs that the suspect may have died in the forest, like buzzards circling overhead.

“We’re going to stay in the woods till we find him, and, you know, that’s our job,” Pennington said. “If he’s dead or alive, it’s our job to try to find him, and that’s what we’re going to do.”