Russell,
My 50+ mile loop goes from Vancouver over I-205 bridge, down to Oregon city – and back.
I return along east side of river through downtown Portland & up I-5 bridge. Or, I cross the bridge at Oregon city, returning through Lk Oswego/SW Portland up I-5 bridge.
There are plenty of designated bike lanes to accomplish this, many are not near vehicles whatsoever.
While you will see a lot of homelessness firsthand, I have never had a problem. I honestly find this much safer than going north. When I go north, I experience tight lanes with little or no shoulder for bikes, big trucks, and even bigger negative attitudes
towards cyclists.
I’ve organized VBC rides into Portland, and would be glad to organize more.
Kevin