Female black widow found in a bag of clothes
Western Black Widow (Latrodectus hesperus). I immediately thought southern black widow because I’m from the south. You are in Colorado. Additionally, the hour glass is irregularly shaped (bigger and squared off on the bottom), which can happen with any widow, but is more common with the western.
Lucky you found her. A lot of spider bites happen because the spider was inside an article of clothing and someone put it on. That, and rooting around in woodpiles barehanded.