This bonus geocache is NOT at the posted coordinates.
First, you will need the Adventure Lab app available from the app store on your smart phone.
You will then need to complete the "20 Years of Geocaching-Greeley Unexpected" Adventure Lab in order to get the final coordinates and instructions on how to access the physical container.
You will have 5 stops to complete before you receive the coordinates. You may retrieve the coordinates at anytime after you have completed the tour by viewing the journal of the "20 Years of Geocaching-Greeley Unexpected" Adventure Lab series. It will be listed on the final entry.
Click here to get started https://labs.geocaching.com/goto/66f7783e-45f8-42b5-a62c-be0b4c8833f7