on ▁was ▁founded ▁and ▁constructed ▁with ▁the ▁coming ▁of ▁rail road ▁in ▁ 1 9 0 6 . ▁ ▁The ▁construction ▁of ▁the ▁Y ellow stone ▁Branch ▁continued ▁from ▁As ht on ▁into ▁the ▁high ▁country ▁of ▁Island ▁Park ▁and ▁completed ▁at ▁West ▁Y ellow stone ▁in ▁ 1 9 0 8 . ▁ ▁A ▁few ▁years ▁later , ▁the ▁T eton ▁Valley ▁Branch , ▁was ▁constructed ▁from ▁As ht on ▁into ▁the ▁Lam ont ▁and ▁T eton ▁Valley ▁areas ▁and ▁completed ▁to ▁Victor ▁in ▁ 1 9 1 2 . ▁ ▁Due ▁to ▁the ▁deep ▁sn ows , ▁however , ▁these ▁two ▁rail ro ads ▁were ▁closed ▁down ▁in ▁winter ▁and ▁not ▁p low ed ▁until ▁spring . ▁ ▁This ▁made ▁As ht on ▁the ▁winter time ▁rail ▁termin us ▁for ▁the ▁entire ▁region . ▁ ▁In ▁winter , ▁mail , ▁people , ▁and ▁supplies ▁could ▁only ▁be ▁transport ed ▁to ▁develop ments ▁in ▁these ▁high ▁country ▁areas ▁via ▁dog ▁s led . ▁ ▁By ▁ 1 9 1 7 , ▁m ushing , ▁in ▁As ht on , ▁was ▁a ▁serious ▁business ▁with ▁do z ens ▁car ving ▁out ▁a ▁living ▁training ▁and ▁maintain ing ▁dog ▁s led ▁teams ▁that ▁transport ed ▁mail , ▁people , ▁and ▁supplies ▁to ▁the ▁high ▁country ▁in ▁winter . ▁ ▁The ▁idea ▁for ▁the ▁first ▁dog ▁s led ▁race ▁has ▁a ▁traditional ▁history ▁that ▁a ▁popular ▁bar ber ▁in ▁As ht on , ▁named ▁Jay ▁Ball , ▁dream ed ▁it ▁up ▁after ▁reading ▁about ▁the