Staffing. As a Preferred Provider of staffing services for VISIT DENVER and with over 50 years of staffing experience, Snelling Personnel is the place to trust with all your convention staffing needs.  With over 250 qualified employees available each week, we stand ready to provide you with registration clerks, room monitors, cashiers, set-up and tear down, bag stuffers, and more.  If you need something special - just ask us.