▁US ▁ 1 2 , ▁through ▁remote ▁mountain ▁forest ▁and ▁up ▁to ▁L olo ▁Pass , ▁was ▁built ▁in ▁the ▁early ▁ 1 9 6 0 s , ▁making ▁US ▁ 1 2 ▁the ▁last ▁US ▁highway ▁constructed . ▁No ▁services ▁are ▁available ▁between ▁Low ell ▁and ▁Pow ell , ▁about ▁▁ ▁further ▁east . ▁U . S . ▁Route ▁ 1 2 ▁through ▁Id aho ▁has ▁been ▁proposed ▁as ▁a ▁route ▁for ▁ship ment ▁of ▁huge ▁equipment ▁from ▁Lew ist on , ▁an ▁in land ▁port , ▁to ▁oil ▁s ands ▁facilities ▁near ▁Fort ▁Mc M ur ray , ▁Al berta ▁and ▁to ▁a ▁ref in ery ▁in ▁Bill ings , ▁Mont ana . ▁On ▁two - lane ▁port ions ▁of ▁the ▁road , ▁the ▁equipment , ▁we igh ing ▁as ▁much ▁as ▁ 3 0 0 ▁tons ▁and ▁as ▁much ▁as ▁ 3 0 ▁feet ▁high ▁and ▁ 2 4 ▁feet ▁wide , ▁would ▁occup y ▁the ▁entire ▁road way . ▁The ▁route ▁is ▁prefer able ▁to ▁other ▁routes ▁due ▁to ▁the ▁lack ▁of ▁under pass es ▁and ▁the ▁great ▁distances ▁involved . ▁The ▁alternative ▁is ▁transport ▁across ▁the ▁Great ▁Pla ins ▁from ▁Texas ▁or ▁New ▁Orleans ▁On ▁U . S . ▁ 1 2 , ▁the ▁major ▁obst acle ▁would ▁be ▁power ▁lines ▁which ▁would ▁have ▁to ▁be ▁raised ▁or ▁buried . ▁That ▁and ▁other ▁alter ations ▁to ▁the ▁highway ▁such ▁as ▁turn outs ▁would ▁be ▁paid ▁for ▁by ▁the ▁companies . ▁The ▁tr uck s ▁would ▁transport ▁only ▁at