west ▁Mont ana ▁in ▁ 1 8 0 5 , ▁they ▁named ▁many ▁rivers ▁— ▁but ▁if ▁they ▁referred ▁to ▁the ▁mountain ▁ranges ▁by ▁name , ▁the ▁names ▁are ▁not ▁recorded . ▁The ▁ 1 8 6 5 ▁De L ace y ▁Map ▁of ▁Mont ana ▁Territ ory ▁does ▁not ▁name ▁the ▁Tob acco ▁Ro ots . ▁The ▁first ▁written ▁reference ▁to ▁the ▁mountains ▁between ▁the ▁Mad ison ▁and ▁Jefferson ▁R ivers ▁is ▁F . V . ▁Hay den ' s ▁ 6 th ▁Ann ual ▁Report ▁of ▁the ▁Ge ological ▁Sur ve ys ▁of ▁the ▁Territ ories ▁for ▁ 1 8 7 3 , ▁in ▁which ▁the ▁name ▁South ▁Bow lder ▁Range ▁is ▁mentioned , ▁a ▁reference ▁to ▁the ▁largest ▁river ▁in ▁the ▁north ▁part ▁of ▁the ▁mountains . ▁Although ▁this ▁usage ▁( us ually ▁sp elled ▁" S outh ▁B ould er ▁Range ") ▁is ▁followed ▁in ▁many ▁Ge ograph ies ▁and ▁Atl ases ▁of ▁the ▁ 1 8 9 0 s ▁and ▁early ▁ 1 9 0 0 s , ▁the ▁US GS ▁Three ▁F ork s ▁Fol io ▁ ▁labels ▁the ▁mountains ▁" J eff erson ▁Range ." ▁ ▁The ▁earliest ▁known ▁use ▁in ▁print ▁of ▁the ▁name ▁Tob acco ▁Root ▁Mountains ▁is ▁Win ch ell ' s ▁( 1 9 1 4 ) ▁report ▁on ▁min ing ▁districts ▁of ▁the ▁D illon ▁Qu ad . ▁The ▁name ▁was ▁also ▁used ▁by ▁Bill ings ley ▁in ▁a ▁ 1 9 1 8 ▁paper ▁on ▁the ▁B ould er ▁B