What do you consider good?? If it is mid winter crisp powder, you are definitely rolling the dice anywhere in Colorado after the middle of March. There is plenty of cold snow right now, but a warming trend can change all that is just a couple of days. The only lock-in that I know of late in the season is the high resort skiing in the Banff area. There you still have the benefit of higher lattitude combined with altitudes that virtually insure crisp light winter conditions well into April.
If you like springtime 'freeze - thaw' skiing, your best bet is probably the big name areas out from Denver like Steamboat, Vail, or Snowmass. Who knows; you might get lucky with the weather and get the best winter skiing of the year while you are there.
Hope you have fun!! [img]smile.gif[/img]