9   km ² ▁( 1 , 7 9 9 ▁sq ▁mi ) ▁of ▁north ▁central ▁Mont ana ▁in ▁the ▁U . S .. ▁They ▁are ▁in ▁Ch oute au , ▁Jud ith ▁Bas in ▁and ▁Cas cade ▁count ies ▁ ▁and ▁lie ▁east ▁of ▁Great ▁F alls ▁and ▁Bent on ▁Lake ▁National ▁Wild life ▁Ref uge , ▁at ▁the ▁northern ▁end ▁of ▁the ▁Lewis ▁and ▁Clark ▁National ▁Forest . ▁The ▁mountains ▁were ▁included ▁in ▁High wood ▁Mountains ▁National ▁Forest ▁until ▁ 1 9 0 8 , ▁when ▁the ▁unit ▁became ▁part ▁of ▁Lewis ▁and ▁Clark ▁National ▁Forest . ▁ ▁Near by ▁are ▁High wood , ▁Mont ana ▁and ▁the ▁Missouri ▁River ▁above ▁the ▁mouth ▁of ▁the ▁Mar ias ▁River . ▁The ▁highest ▁point ▁in ▁the ▁High wood ▁Mountains ▁is ▁High wood ▁Bald y ▁at ▁ 2 3 3 8 ▁meters ▁( 7 6 7 0   ft ). ▁ ▁The ▁area ▁has ▁vol can ic ▁orig ins ▁and ▁is ▁rich ▁in ▁pot ash . ▁Many ▁of ▁the ▁extr us ive ▁rocks ▁and ▁some ▁of ▁the ▁di ke ▁rocks ▁contain ▁abund ant ▁phen oc ry st s ▁of ▁a ▁clear ▁anal c ime ▁that ▁appears ▁to ▁be ▁primary . ▁Pseud ole uc ite ▁is ▁an ▁abund ant ▁constitu ent ▁of ▁many ▁of ▁the ▁ igne ous ▁rocks . ▁The ▁Sh on kin ▁S ag , ▁a ▁gla cial ▁m elt water ▁channel , ▁borders ▁the ▁High wood ▁Mountains ▁to ▁the ▁north . ▁ ▁See ▁also ▁ ▁List ▁of ▁mountain ▁ranges ▁in ▁Mont ana