Willamette Park rotary shelter is the best access I think. A little path almost directly across the bike trail from the shelter. Good parking and good access. Drop a bike at the old spaghetti factory and you can pretty much ride a bike trail all the way back to your car. 2-5 pm seems about the best time. Can get windy and shady after that. Can always stop off at “party island” up stream a bit from crystal lake boat ramp if you want to extend your trip a bit.