Colorado Early September @ 10,500+ ft... Average monthly temps near our location. September Avg High=57.0 °F Average low=33.0 °F Record High=81.0 °F Record low= 13.0 °F (09/19/1971--09/14/1990)

You have a 0 degree marmot or a 15 degree marmot bag to choose from. The 15 degree saves you 1.5 pounds of weight and you already have a heavy load to carry so saving weight is good.. You typically get cold easy when sleeping as well. you will be sleeping in a Clark NX-250 with either a thin sleeping pad under you or perhaps you upgrade to the z-liner..

Anyway just worried I could get cold this time of the year and not sure what bag to pack or if I need to upgrade to the z liner from clark or an UQ.. choices choices and $$ it cost. Thanks for any advice for those that have had the same choices.. flame away..lol