I'm in the same neck of the woods you are, takes me about 5-10 minutes to drive to the 205 bridge on Marine Drive. Last time I went ther eI ended up paying a deductable to have my windows replaced. You can try Kelly Point park, but that's up in North Portland, might be a bit of a drive. There's always Chinook Landing, yes it's a boat ramp, but plenty of people fish there, or probably your best bet depending upon time oyu have is go out at thehead of the runway at Troutdale airport, and then walk accross that huge field, right down to where the sandy and columbia meet. All along Marine Drive is pretty much shut down by the Port of Portland for fear someone will shoot down an airliner. About your only shot is Chinook Landing or 205 bridge. There is a little pulloff there on Marine Drive by the bike pathw here a lot of cyclists park their cars, there is also a lot of window glass on the ground. If you ever want to meet up and head somewhere to go fishing my days off are Friday and Saturday. I generally don't go too far, and I fish for pretty much everything from Carp, to trout, to salmon/steelhead, to perch bass and catfish.
