Going to Lake Tahoe in August and want to make the most of a 4 day trip. I really would like to go to San Fran, Napa and/or Spa. However, I keep reading about Yosimite. Now Im all confused. Can anybody send a good 4 day trip. Ill be flying into Reno and possibly renting a car. This is a special trip for me and my mother who will be celebrating her birthday.