I encounter this question a lot in the bicycle law clinics I teach.
The short answer is: No. There is no statewide legal requirement to walk a bicycle in a crosswalk.
There are, however, a couple of laws to keep in mind when riding up to or in a crosswalk.
First, when a bicyclist in Oregon is riding on a sidewalk and is approaching or entering a crosswalk (and also a driveway, a curb cut, or a pedestrian ramp) and a motor vehicle is approaching, the bicyclist must slow to the speed of an “ordinary walk” while approaching and entering. ORS 814.410(1)(d) Unsafe operation of bicycle on sidewalk.
Second, a bicyclist is entitled to the same rights and responsibilities as a pedestrian while in a crosswalk. ORS 814.410(2). What this means is that the requirement that a motor vehicle stop at a crosswalk when a pedestrian is crossing the roadway also applies to bicyclists. ORS 811.028 Failure to stop and remain stopped for pedestrian. Oregon law even requires cars to stop when any part of a person’s bicycle moves onto the roadway in a crosswalk with the intent to proceed across. ORS 811.028(4). A bicyclist can’t leave the sidewalk into the path of a car, though, if the car is so close it constitutes an immediate hazard (like it wouldn’t be able to stop safely), even if the bicyclist is entering a crosswalk. ORS 814.410(1)(a).
Third, a bicyclist must always keep in mind that while riding on the sidewalk and in crosswalks is legal under state law, cities have the right to make it illegal under their city ordinances, so it is important to know the laws of the cities you ride in.