Obviously Brak has never been to Lake Tahoe either. Spring in Lake Tahoe can still get quite chilly. DO NOT pack t-shirts and shorts. Think about dressing in layers. The nights get cold, but the days may be mild. Take slacks, jeans and what you would usually match them up with, plus a sweater, or warm jacket. If you re 21 or older, and you plan to go into any of the casino s also take something dressy.
Take some t-shirts, some shorts or capris. Some strong shoes for walking. Make sure you wear socks with those shoes too especially if you will be hiking or walking a lot.And you should also pack some comfortable panties.I think they have mild weather in March.
Do a search for lake tahoe weather and you should be able to find a site that gives you average highs and lows for the period you will be there. Plan accordingly.
Its in the mountains and their is skiing, so I would bring clothes for fall/winter weather.