Colorado mountain summer sleeping bags?

Colorado sleeping bags? The last time I went backpacking I was learning MS Windows 3.1, there was a Soviet Union and no internet.
I love hiking, and my girl and I want to backpack in to the high mountains of Colorado.
I would really like some help on gear.
First off, What sleeping bag do we need to sleep comfortably.
What works for the high country in the summer?
We want to be warm enough, dry enough and lightweight?
Anyone have some practical experience to help us out?
Joe

I sleep somewhat cold but have always been comfortable in a good 20 degree bag in the Rockies. It used to be a Feathered Friends Swallow, now a Western Mountaineering Ultralight.

I have lived and backpacked in Colorado, in all four-seasons, for the past decade or so and I wouldn't recommend anything other than +15-25 degree bag for a Colorado summer.

I have woken up countless times in June and July to frost on the ground. In fact just last June I was caught in a freak hail and snowstorm. What I am trying to get across is that a traditional summer bag of 30-40 degrees will just not cut it in Colorado, except in the height of summer.

As for "light"-- that is a subjective term. Personally speaking, I consider a light 3-season bag anything under 3lbs. Others may say different. However, how light you can go will depend on your budget, generally speaking the lighter the bag, the more expensive it is.

With that said-- the REI Sub-kilo is a great first choice-- inexpensive and light-- they are just a bit narrow.

http://www.rei.com/search?query=sub+kilo&button.x=0&button.y=0

If you have the time then Golite currently have a warehouse sale going on in Northglenn and Littleton. They have a synthetic 3-season bag going for $100 or a down 3-season bag for $150 or a down version for $130. These prices are only available at the aformentioned loctions

Down
http://www.golite.com/Product/ProdDetail.aspx?p=161003110
Synthetic
http://www.golite.com/Product/ProdDetail.aspx?p=163001110&mc=206&t=&lat
Sale locations:
http://www.golite.com/sale/

+1 on Feathered Friend's sleeping bags, I own both their Swift and Peregrine and both are very high quality bags. However I have recently switched out my Swift for a Golite Ultralight 3-season quilt that I picked up at the warehouse sale-- saves me over a pound in weight.

I was looking at the WM Ultralight as my Swift replacement, but couldn't pass up the quilt for $150 verses $400 for the Ultralight.

I grew up in Wyoming and spent summers in the Colorado Rockies when growing up. Much more recently, I've taken several trips back to Colorado and to Wyoming's Wind Rivers.

A 20* Western Mountaineering Ultralight works fine for me. There were a few times that it was a bit marginal even with a vapor barrier suit and all my insulating clothing, but most of the time I was snuggly warm. IMHO, the most wonderful thing about this bag is the draft collar!

As mentioned, there will be a lot of frosty nights at higher elevation, and it can snow any time during the summer. Be prepared!