Best Ski Resort within 1.5 hour drive of Boulder?

Winter Park!  Lots of powder - some of the best tree skiing in the state.  If she is just looking for advanced skiing park at the base of Mary Jane rather than the main base at Winter Park.

 I go to college at CU Boulder and have lived in Colorado my entire life, so I know my way around pretty well!  Eldora Mountain Resort is the closest to Boulder, about 35 minutes. However, it is much smaller than popular resorts like  Vail (which is a great place to ski, but one of the most expensive), but you can ride the RTD to Eldora and can avoid I-70 all around! My favorite in Colorado is  Winter Park- you can stay on the easier runs of  Winter Park or ski over the mountain to the harder  Mary Jane Ski Area.  Ski Granby Ranch (formerly Sol Vista) is just past Winter Park and is smaller and cheaper. If you go to any resort off of I-70, I recommend hitting  Beau Jo's Pizza in  Idaho Springs on your way back down and get a big Colorado style pizza. Happy skiing!

Best backcountry access is from Arapahoe Basin Mountain or just drop off the road from the top of Loveland Pass. Loveland pass is nice because you can ski from the road to the road and either hitchhike back up to your car, or shuttle cars with a few friends. BE CAREFUL......Summit County Colorado has the highest avalanche death toll in the state (maybe country) so don't ski in the backcountry unless you are prepared and know what you're doing.

I went to college in Boulder, and was lucky enough to take advantage of the amazing skiing and snowboarding options!

My top recommendation for a skier is Vail. It is about 2 hours away from Boulder, but worth the extra 30 minutes.

I'd recommend starting in Lionshead, which has a gondola with quick access to the backside of the mountain. The Vail back bowls are unreal for advanced skiers that want to huck some cliffs--my favorite being China bowl. The views are beautiful, and she will find plenty of powder and black diamond runs. And when she wants a break, she can head to Garfinkel's Bar & Grill for a tasty adult beverage at the base of the mountain.

We thoroughly enjoyed Steamboat Springs with its champagne powder. Fantastic!

Arapahoe Basin Mountain or Keystone Ski Resort are usually best. Breckenridge Ski Resort can get a little tourist-y, but still has a number of runs that would be great.  Breck does have a great little mainstreet with plenty of bars and restaurants, though.

Winter Park is the closest to Boulder and is really fun - Mary Jane is the more advanced area of that resort.  All of the major resorts along I-70  ( Keystone (Colorado) Breckenridge Copper Mountain, ) are awesome, giving the skier/boarder many options for ease, endurance, challenges, and bars!    For me and my "groupies", Vail is the best.  It has so much variety that no two days are the same!  It is a bit farther - probably closer to 2 hours - but totally worth it!

As for lots of powder, just be ready to rock-n-roll at the mention of a pending storm!  Try 'em all and pick YOUR best...ENJOY!