Lots of powder is a challenge in the Tahoe region. It does happen (like this week), but is rare in March due to when it snows in March, its generally of the heavy wet variety vs the champagne powder we get here in Colorado due to the additional moisture coming off the ocean.
If you want degree of difficulty..challenging black diamonds on solid steeps, Squaw is your place. If you like nice groomers, Northstar can't be beat.
The driest and most likely place to find powder is just south of Reno at Mt. Rose. Being the most eastern ski area has its advantages. Mt. Rose and Alpine Meadows is where you will most likely find the locals and get you off the beaten path so to speak.
I ski at Heavenly, mainly because my Colorado pass gets me cheap lift tickets there. But its also one of the largest, has gorgeous views back at the lake and a wide variety on the south shore.
