The Millcreek Canyon Road is closed and groomed in the winter from the winter gate at the top. It is about 9miles/1500ft elevation out-n-back, with a good amount of parking.
Pipeline Trail can be accessed near the bottom of Millcreek Canyon at the first parking lot or halfway up the canyon. From the bottom, the ride is a 15-mile/1400ft elevation out-n-back. The top of Pipeline comes out at the groomed Millcreek Canyon Road, so you could extend your ride.