cindy sauders, national fish and wildlife service ranger on the rocky flats nuclear sites transition into a national wildlife refuge. >> so we do have ilk that use this area. they use drainages for cabbing. we have also mill deer so there may be mill deer farms out here. coyotes are other common mammals. occasionally there is a bear in this area. >> then kimberly field, author of "the denver mint -- 100 years of gangsters, gold and ghosts." talks about how mint changed the city. >> by the 1880s, denver itself had gotten rich from mining, and it wanted to become the queen city of the plains, center of commerce, the leader in the western united states. and the city founders at that point decided that a mint that they could be proud of was going to be part of that process. >> c-span cities tour of denver, colorado, saturday at noon eastern on c-span2's bob ok tv. sunday afternoon on american history tv. working with cable affiliates and visiting cities across the country. >>> on lectures in history, iowa state unive