For some good urban hill climbs around Portland, try:

RondePDX

It looks like they've mapped out 5 routes around Portland.

Each ride is about 50 miles, and about 7,000 feet of climbing. The rides are free. Different dates, but you can also just go whenever you want using route software and following street markings.

Most of the time you're either going UP or DOWN. And, if going down, then right around the corner, and it is back up again. Lots of climbs around 10%, and a few in the 20% to 30% range.

For me, a half century of hills was adequate for a good ride.

It is mostly paved, but plan on a few short sections of dirt or gravel.