Parking can be found at Kelley Point Park (N. Marine Drive and Lombard Street) and Delta Park (10737 N. Union Court).
The first part - Vancouver Avenue to Interstate Avenue was fine, new macadam. The part from Interstate Avenue to Portland Road was needs repaving, with gravel between patches of macadam in bad shape. Given that your on top of a narrow lever, it was bit dicey.
Best access point is parking at Columbia Boulevard Water Treatment plaint and following the path and bridge across the slough. A little industrial in parts, but beautiful views of the slough and lots of birds (great blue herons, great egrets, hawks, sandpipers, etc.) and other animals (river otters, nutria, etc.). You'll have the trail mostly to yourself. I'd recommend going during the week to avoid going on a day where the raceway is up and running. Great hidden gem.
Industrial for huge parts. Not the prettiest bike ride.
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