▁highway ▁cross es ▁the ▁Great ▁Pla ins , ▁connecting ▁Den ver ▁with ▁metropol itan ▁areas ▁in ▁Kansas ▁and ▁Missouri . ▁B icy cles ▁and ▁other ▁non - mot or ized ▁vehicles , ▁normally ▁prohib ited ▁on ▁Inter state ▁High ways , ▁are ▁allowed ▁on ▁those ▁st ret ches ▁of ▁I - 7 0 ▁in ▁the ▁Rock ies ▁where ▁no ▁other ▁through ▁route ▁exists . ▁ ▁The ▁U . S . ▁Department ▁of ▁Transport ation ▁( US D OT ) ▁lists ▁the ▁construction ▁of ▁I - 7 0 ▁among ▁the ▁engineering ▁mar vel s ▁undert aken ▁in ▁the ▁Inter state ▁Highway ▁system , ▁and ▁c ites ▁four ▁major ▁accomplish ments : ▁the ▁section ▁through ▁the ▁Dak ota ▁Hog back , ▁Eisen h ower ▁T unnel , ▁V ail ▁Pass ▁and ▁Glen wood ▁C any on . ▁The ▁Eisen h ower ▁T unnel , ▁with ▁a ▁maximum ▁elev ation ▁of ▁ ▁and ▁length ▁of ▁, ▁is ▁the ▁longest ▁mountain ▁tunnel ▁and ▁highest ▁point ▁along ▁the ▁Inter state ▁Highway ▁System . ▁The ▁portion ▁through ▁Glen wood ▁C any on ▁was ▁completed ▁on ▁October ▁ 1 4 , ▁ 1 9 9 2 . ▁This ▁was ▁one ▁of ▁the ▁final ▁pieces ▁of ▁the ▁Inter state ▁Highway ▁System ▁to ▁open ▁to ▁traffic , ▁and ▁is ▁one ▁of ▁the ▁most ▁expensive ▁rural ▁high ways ▁per ▁mile ▁built ▁in ▁the ▁United ▁States . ▁The ▁Colorado ▁Department ▁of ▁Transport ation ▁( CD OT ) ▁earned ▁the ▁ 1 9 9 3 ▁Out standing ▁Civil ▁Engineering ▁Ach iev ement ▁Award ▁from ▁the