Do you want to have a chance at catching some fish?
I am going to guess (you can correct me if I'm wrong) that you are throwing a 5wt... yes? If you are, then your chances on the Willamette are slim...or none.
No car? $5.- will buy you an Adult All Zone pass on Tri-Met...busses, light rail, it covers all their routes. So here are 4 just off the top of my head;
#20 will get you within striking distance of the Sandy River (you might have to walk a few blocks)
#30 will get you to Estacada and within striking distance of a good portion of the lower Clack.
#33 will get you Oregon City and I think you can transfer to get to Mollala and within striking distance of the Mollala River.
Westside Max+ #57 will put you within striking distance of Dairy Creek and west side farm ponds.
AND... if a guy had a Mountain Bike, which can be taken on most Tri-Met bus/light rail.... well he could do some damage.
That fare is good from like 5am till 11pm or midnight...all day, all zones.
Leave the Will-a-met to the bait fisherman...