You will want a fire in the Sawtooths at that time of year. I camped up there a couple of weeks ago, and it was in the 40's at night. This is when it was in the 100's during the day here in the valley. Stanley(right at the foot of the Sawtooths), is usually on the nations extremes for the coldest temps. Make sure that your bag is a good one, and you just may have to fire up the heater to thaw out your water. I hunt in an area that is close to the temps that the Sawtooths have, and had to skip the teeth brushing because the toothpaste was frozen. Beautiful country though and lots of elk....................