Welcome to the forum. At this time of year; you are relegated to lakes. Most streams won't open, until May 24th. But, a few streams ARE open on April 26th.
It's also worthy to note that, you can keep 5 trout per day from a lake. But most streams are catch and release only. All of this is explained, in the reg book. Do you have a copy?
Have you checked ODFW's lake stocking schedule, for trout? If you prefer non-hatchery bred fish; I say head up to Lake Harriet. It's about an hour past North Fork Reservoir, in the Clackamas basin. Or, there is Hagg Lake just SW of Forest Grove. There's a $5 daily fee. But, I love Hagg (was trolling it on the opener on 3/1). Saw an 11-pound one-year hold-over 'bow caught there, last year on the opener. Yes. I said 11 POUNDS. There are bigger trout in there too. But, you'll mostly get truck trout (or some 17-18" hold overs).
Tight lines.