Whats the consensus on the proper rating for a sleeping bag to be used in Yosemite, Yellow Stone, Mammoth, JMT late spring through mid-fall?
I don't want to get a bag that is too hot or too cold. I like to be warm when i sleep, but I guess i can always layer up in extreme cases. It's easier to unzip the bag than carry extra clothes if it's not properly rated IMHO.
So - 15*, 20*, 30*...?