This looks like one of the ground spiders. Getting a more accurate identification would require submitting a specimen for identification. CSU's Plant Diagnostic Clinic (https://plantclinic.agsci.colostate.edu/) provides arthropod id services. The Denver Museum of Nature and Science is another possibility.
Since you are in Jefferson county, you may also submit a specimen for identification to the CSU Extension Jeffco Plant Diagnostic Clinic ($7 fee for Jeffco residents) located at the Jeffco fairgrounds.