▁Some ▁b ogs ▁are ▁also ▁present ▁in ▁this ▁area . ▁W et lands ▁near ▁the ▁stream ' s ▁head w aters ▁include ▁the ▁Y ost ville ▁mar sh es . ▁In ▁the ▁stream ' s ▁middle ▁and ▁lower ▁reaches , ▁its ▁valley ▁is ▁fl ank ed ▁by ▁ste ep , ▁high ▁mountains . ▁Its ▁channel ▁is ▁sin uous ▁and ▁flows ▁through ▁rock ▁form ations ▁consisting ▁of ▁sand stone ▁and ▁sh ale . ▁There ▁is ▁also ▁some ▁coal ▁in ▁the ▁lower ▁reaches ▁of ▁the ▁waters hed . ▁There ▁are ▁some ▁cul m ▁d umps ▁along ▁the ▁stream ▁between ▁Pennsylvania ▁Route ▁ 5 0 2 ▁and ▁US ▁Route ▁ 1 1 . ▁ ▁Spring ▁Brook ▁flows ▁across ▁the ▁Po cono ▁Pl ate au ▁and ▁passes ▁through ▁the ▁Mo os ic ▁Mountains ▁via ▁a ▁water ▁gap ▁known ▁as ▁the ▁Spring ▁Brook ▁G ap . ▁Its ▁mouth ▁is ▁in ▁the ▁L ack aw anna ▁Valley . ▁In ▁its ▁lower ▁reaches , ▁the ▁stream ▁is ▁channel ized ▁in ▁a ▁large ▁open ▁concrete ▁channel . ▁A ▁number ▁of ▁bank ▁stabil ization ▁projects ▁have ▁been ▁done ▁on ▁the ▁stream ▁from ▁Berlin ▁Village ▁down stream ▁to ▁its ▁mouth . ▁Some ▁land ▁in ▁the ▁vic inity ▁of ▁the ▁stream ▁is ▁designated ▁as ▁a ▁ 1 0 0 ▁year ▁flo od plain . ▁ ▁There ▁are ▁a ▁number ▁of ▁d ams ▁on ▁Spring ▁Brook . ▁One ▁of ▁these ▁is ▁the ▁Spring ▁Brook ▁In take ▁Dam , ▁which ▁was ▁determined ▁in ▁ 1 9 8 0 ▁to ▁be ▁in ▁good ▁condition . ▁Another ▁is