Despite the images, the area had never been formally explored because of the challenging terrain.

This allows the operator to make the most of the engine's available power while moving slowly through challenging terrain.

They walked through some of the most challenging terrain on earth.

"We needed steep and challenging terrain, and the new slopes were made to order."

It offers an array of challenging terrain and conditions.

Gone are the nightmares she used to have about driving a 13-ton bus through challenging terrain.

When traveling vast distances over challenging terrain, the people left nothing behind.

It contains challenging terrain that is very close to campus.

The Arctic is a very challenging terrain and in order to face it you need to be with the right people.

It is primarily used to move material short distances or through challenging terrain.