I hike Keystone. Some of the stuff I go to you can take Cat rides too. I would not take a cat ride from Outback to the North and South Bowls, the hike is not bad. Most of this will be open bowl riding. Most of the terrain dumps into trees. There are catwalks out that suck. Most of the tree riding in the back mountains is old growth and farther apart. There are easy tree escapes, but you should be comfortable in trees. You should be a rider with good control.
Also currently there is a low snowpack. I have not been hiking or riding trees at Keystone. Do your snow dances. I have done some tree riding earlier around Christmas and hit stumps. We have not gotten the snow yet to cover it up good. Some areas have many downed trees.
IT AINT EAZY BEIN STEEZY