Attempted to ride at Willowdale today and the surface of the snow packed trail was crusty enough to support me and my bike but was unfortunately pot-holed by deep frozen foot prints. If you had a 29" bike or fat wide snow bike style tires you would have better results. I rode about 1/2 mile or so of the single track. The fire roads were packed down well and it seemed as though someone had been through with a snowmobile of some sort to smooth a path which made the fire roads very rideable. This is all hit or miss of course depending on where you are in the park. I only rode a very short percentage of the trails because I don't enjoy riding fire roads and my 26" studded tires were just getting bogged down by the frozen pot holes on the single track trails.