montana highway montana highway primary state highway located southwestern region state montana highway travels mainly rural areas pass montana idaho state line intersection route travels portion road location added highway system years later road designated portions early auto trails route rapidly improved collapse nearby highway reconstructed current location route description begins montana idaho state line traveling pass highway proceeds northward intersecting small road entering rural areas route continues northeast intersecting forest roads bending northwestward route intersects small roads runs parallel small creek crosses passing small buildings highway continues northwestward northern terminus grade intersection highway maintained job measure traffic highway counts taken metric called annual average daily traffic aadt statistical calculation average daily number vehicles travel portion highway highway aadt count vehicles portion highway listed national_highway_system network roads important country economy defense mobility history october road located general location added system auto trail known grand canyon road ran highway general location year highway given graded dirt surface designated great white way auto trail grand canyon road auto trail designations removed stretch highway near present day main highway shifted north location numbered state highway road remained location road extended miles northward highway reconstructed generally present location upgraded improved gravel road road location rapidly improved order serve alternate routing route portions collapsed result lake earthquake fixed highway importance decreased portions highway southern terminus present day reconstructed current location rest highway reconstructed present location highway numbered route paved major intersections
Montana Highway 87