Replying to Park and Ride at the base of Cottonwoods??

Hey guys,

I'm heading to SLC on Monday and plan to ride Big/Little Cottonwood. Last time I was there I just drove up the canyon roads to the resort (weather was good.). But, its looking like it might be a snowy first few days and my rental car is a bit sketch. So i'm wondering how the Park and Ride and the base works? I remembered seeing them right at the mouth of the canyon road.

Do you have to pay? Are they UTA buses? How often do they come?

Thanks dudes!