( ( Mountain ( ( lakes and ) streams ) ) ( ( were ( ( used ( most often ) ) ( during ( the fall ) ) ) ) . ) )
(ROOT (S (NP (NNP Mountain) (NNP lakes) (CC and) (NNP streams)) (VP (VBD were) (VP (VBN used) (ADVP (RBS most) (RB often)) (PP (IN during) (NP (DT the) (NN fall))))) (. .)))
Mountain lakes and streams were used most often during the fall.
(ROOT (S (NP (NNS Streams)) (ADVP (RB often)) (VP (VBP start) (PP (IN in) (NP (NNS mountains)))) (. .)))