At the end of the Snowmass Mall there are a few Big Box name stores but these are the good ones and you won’t feel bad shopping there.
One is Patagonia and with a reputation for sustainability it is always great source for outdoor gear and clothing. Patagonia prides itself on transparency and makes and an effort to minimize the over encompassing footprint of their business. You can shop there and feel good that you are making an effort in environmental issues.
The other is North Face which is built to endure and aid you in the toughest conditions and if you aren’t used to the cold they are good apparel to sport. They design it with the pursuit to get people outdoors. I know that I love my Summit Series down jacket. It got me to the top of Kilimanjaro.