 Colorado held several meetings to convince reluctant Utah officials they would benefit from a freeway link between Denver and Salt Lake City . Utah officials expressed concerns that , given the terrain between these cities , this link would be difficult to build . They later expressed concerns that the construction would drain resources from completing Interstate Highways they deemed to have a higher priority . Colorado officials persisted , presenting three alternatives to route I @-@ 70 west of Denver , using the corridors of US 40 , US 6 and a route starting at Pueblo , proceeding west along US 50 / US 285 / US 24 . In March 1955 , Colorado officials succeeded in convincing Utah officials with the state legislature passing a resolution supporting a link with Denver . The two states jointly issued a proposal to the U.S. Congress that would extend the plans for I @-@ 70 along the US 6 corridor . Under this proposal the freeway would terminate at I @-@ 15 near Spanish Fork , Utah , linking the Front Range and Wasatch Front metropolitan areas . 
