I think a trail horse should be able to handle steep, rocky and slippery terrain. I like knowing that my horse will find his footing and step easy. I ride a walking horse...I love his running walk, but when I say walk, I mean for him to do it slow and easy. I think for safety reasons it is best to have a horse that doesn't overreact when spooked. No matter how long your horse has been on the trail, sooner or later your gonna come up on something that surprises or spooks him. Horses will react of course, but some will get really crazy.