▁are ▁mostly ▁for ested ▁with ▁native ▁Big leaf ▁Map le , ▁Douglas ▁Fir , ▁Grand ▁Fir , ▁Western ▁Hem lock , ▁Western ▁White ▁P ine ▁and ▁Western ▁Red ced ar . ▁ ▁Non ind igen ous ▁trees ▁include ▁Coast ▁Red wood , ▁Inc ense - ced ar , ▁and ▁Western ▁L arch . ▁ ▁There ▁are ▁work part ies ▁in ▁the ▁park ▁held ▁by ▁the ▁Seattle ▁Park s ▁Department , ▁particularly ▁in ▁April ▁and ▁May . ▁A ▁volunte er ▁group , ▁Fri ends ▁of ▁R aven na ▁Rav ine , ▁works ▁to ▁remove ▁invas ive ▁species , ▁such ▁as ▁English ▁I vy ▁and ▁H imal ay an ▁Black berry ▁from ▁the ▁park ▁and ▁restore ▁native ▁veget ation . ▁ ▁References ▁ ▁Foot notes ▁ ▁General ▁references ▁▁▁▁▁▁▁▁▁ ▁Cow en - R aven na ▁Park ▁Tra il ▁Map , ▁Seattle ▁Park s ▁and ▁Rec re ation . ▁ ▁External ▁links ▁ ▁Category : P arks ▁in ▁Seattle ▁Category : R av ines ▁Category : R aven na , ▁Seattle <0x0A> </s> ▁Harold ▁Sw anson ▁( c . ▁ 1 9 1 3 ▁– ▁? ) ▁was ▁an ▁American ▁football ▁coach . ▁ ▁He ▁served ▁as ▁the ▁head ▁football ▁coach ▁at ▁Manchester ▁College — now ▁known ▁as ▁Manchester ▁University — in ▁North ▁Manchester , ▁Indiana ▁from ▁ 1 9 4 7 ▁to ▁ 1 9 4 8 ▁and ▁at ▁North ▁Park ▁College — now ▁known ▁as ▁North ▁Park ▁University — in ▁Chicago , ▁Illinois ▁from ▁ 1 9 5 8 ▁to ▁ 1 9 6