Originally Posted by Harry Dunn
You can hike up all day and ski down if you want. Its Nat'l Forest land- they can't stop you.
Haven't we beat this myth into the ground enough?
No, you can't just do whatever you want because it's a National Forest. You don't have some God given right to go anywhere. Ski areas have special use permits and can limit what activity takes place. For example, you can't just go hiking wherever you want because a portion of the mountain may be closed (for an event, for safety, etc). In that case, you're in violation of the Skier Safety Act. Likewise, you can't cross into or out of a ski area boundary in most places in Colorado; with exceptions like backcountry gates.
While most ski areas have provisions that allow people to just skin up the mountain, they don't necessarily have to do that. Some mountains are known to be friendlier than others concerning that policy. I think Breck is the best around here, they routinely publish hours of when you can access certain areas and update rules about what you can and can't do.
Lift tickets and passes are generally for use of any amenities of the resort, including things like on-mountain restrooms. Anything else you do on the mountain falls under the jurisdiction of the people who own the land.