Lots of you know this already but this is an especially sensitive time of year for nesting owls. With all bird species I'm familiar with (i.e., I've studied their nesting ecology and/or read scientific literature), they are much more likely to abandon a nesting attempt early in the nesting cycle - i.e., during courtship, nest-building, and early incubation. And, since many owls begin nesting quite early (as early as January for Great Horned and a month or 2 later for some others), the next couple months are the time when most owls will feel most vulnerable or stressed.
For owl species that nest in shorter trees/shrubs (i.e., willows) and/or in smaller thickets of vegetation surrounded by open country, they have less room to hide and are more likely to flush when approached by a human or predator. If they do flush, I imagine it's likely much more stressful than for a forest owl flushing from one tree to the next. Importantly, flushing can expose them to diurnal predators, including ravens. Even if they aren't being flushed each time, for owls are nesting in a popular birding area there's potential for repeated visits (by different birders or the same person/people returning to a favorite birding site) to cause a much higher cumulative stress load than a site than only receives an occasional visitor - and this could lead to a failed or abandoned nesting attempt.
I say all this to suggest that people be careful/deliberate in approaching known or suspected nesting sites. Any isolated clumps of willows or other shrubs/trees could be suitable nesting habitat. I'm including a couple pictures that Heidi has from fieldwork around the state that show potential nesting habitat. And, for fun, a picture of a fledgling Saw-whet I found during some surveys many years ago in a riparian draw many miles away from conifer forest (this was June and after fledging so a less stressful time for this bird & its parents - but I still backed away quickly to keep it from flushing).
If you do see an owl, please keep your distance. After all, we all care about birds and know that they have many additional stressors in this modern world. And, what's more important? A better look at or photo of an owl or birds being able to nest in peace without too much disturbance/too many approaches?
Thanks for your time and please feel free to pass this on!