I know several places have 1 day events after the lifts close.  Here are the ones I know. 

4/19 - Seven Springs - Mash Potato Meltdown

4/26 - Mad River (Ohio) - Picnic in capital park 

5/1 - Big Boulder - May Day 

ParkCrewDrew wrote:

I know several places have 1 day events after the lifts close.  Here are the ones I know. 

4/19 - Seven Springs - Mash Potato Meltdown

4/26 - Mad River (Ohio) - Picnic in capital park 

5/1 - Big Boulder - May Day 

OK, this one is too easy.

4/5 - Timberline, WV - Snowmobile races