Colorado State have put out guidelines for people with mild, more serious and severe symptoms. This guidance describes the symptoms, and helps you decide what actions to take:

https://covid19.colorado.gov/press-release/state-health-department-provides-guidance-those-covid-19-symptoms-including-when-call

Local Open Space have put out guidance for staying safe while on open space:

https://www.boulderoem.com/stay-safe-while-recreating-on-open-space/

and here are a couple of short/simple helpful CDC videos: