 Denver 's position near the mineral @-@ rich Rocky Mountains encouraged mining and energy companies to spring up in the area . In the early days of the city , gold and silver booms and busts played a large role in the economic success of the city . In the 1970s and early 1980s , the energy crisis in America and resulting high oil prices created an energy boom in Denver captured in the soap opera Dynasty . Denver was built up considerably during this time with the construction of many new downtown skyscrapers . When the price of oil dropped from $ 34 a barrel in 1981 to $ 9 a barrel in 1986 , the Denver economy dropped with it , leaving almost 15 @,@ 000 oil industry workers in the area unemployed ( including former mayor and current governor John Hickenlooper , a former geologist ) , and the highest office vacancy rate in the nation ( 30 % ) . Since then , the industry has recovered and there remain 700 employed petroleum engineers in the region . Advances is hydraulic fracturing has made the DJ Basin of Colorado into an accessible and lucrative oil play . Energy and mining are still important in Denver 's economy today , with companies such as EnCana , Halliburton , Smith International , Rio Tinto Group , <unk> Mining , Noble Energy , and Anadarko headquartered or having significant operations in the area . 
