▁the ▁rails ▁spac ed ▁three ▁feet ▁apart . ▁The ▁line ▁ran ▁from ▁Den ver ▁south ▁to ▁P ue blo , ▁and ▁then ▁turned ▁west ▁through ▁the ▁Royal ▁G orge ▁to ▁Sal ida . ▁The ▁route ▁then ▁continued ▁over ▁Marshall ▁Pass ▁to ▁G unn ison , ▁Mont rose , ▁and ▁Grand ▁J unction , ▁before ▁entering ▁Ut ah ▁and ▁proceed ing ▁to ▁Salt ▁Lake ▁City ▁and ▁Og den . ▁This ▁existed ▁as ▁a ▁through ▁route ▁only ▁until ▁ 1 8 9 0 , ▁when ▁the ▁main ▁line ▁was ▁standard - g aug ed . ▁The ▁standard ▁gauge ▁route ▁head ed ▁north ▁from ▁Sal ida ▁via ▁Tennessee ▁Pass , ▁rejo ining ▁the ▁original ▁narrow - g au ge ▁route ▁at ▁Grand ▁J unction . ▁This ▁left ▁the ▁old ▁narrow - g au ge ▁line ▁over ▁Marshall ▁Pass ▁as ▁a ▁local ▁route . ▁N arrow - g au ge ▁trains ▁operated ▁between ▁Sal ida ▁and ▁Grand ▁J unction ▁until ▁the ▁Mont rose - Gr and ▁J unction ▁tracks ▁were ▁standard - g aug ed ▁in ▁ 1 9 0 6 , ▁trunc ating ▁the ▁narrow - g au ge ▁line ▁to ▁a ▁Sal ida - Mont rose ▁route . ▁ ▁N arrow - g au ge ▁trains ▁ 3 1 5 ▁and ▁ 3 1 6 , ▁carrying ▁coach es ▁and ▁a ▁par lor ▁car , ▁operated ▁between ▁Sal ida ▁and ▁Mont rose ▁until ▁August ▁ 1 9 3 6 , ▁when ▁the ▁G unn ison - Mont rose ▁portion ▁of ▁the ▁route ▁was ▁dis cont