e-ATF Web Updates What's new on ATF.gov The Denver Field Division is responsible for ATF criminal enforcement and industry regulatory activities in the states of Colorado, Montana, Utah and Wyoming. ATF's Denver Field Division special agents combat firearms violence by focusing their investigative efforts on armed violent offenders, career criminals, gun traffickers and gangs. The workforce is comprised of special agents, investigators, auditors, technicians and support staff. We encourage all residents to get involved and assist us in our goal of reducing crime in our neighborhoods by anonymously submitting information through our new ATF Tips app ( Android and iOS ), visiting the reportit website , submitting an anonymous form , or by reaching out to your local field office . Give us a call and let us know what we can do for you. Our phone number is (469) 227-4300. ...