I would find it very stressful taking toddlers on the tours we were on (Portland City a.m. + Columbia Gorge, Multnomah Falls p.m.). I’m pretty sure you would have to bring your own car seats, and, while much of the city tour is spent just driving around, you do stop and walk around at three sites, one of which is a historic mansion where you are not allowed to touch anything. The Gorge and waterfalls tours involve viewing the sites from tall heights. I witnessed one toddler pushing almost half his body through the bridge while looking at one of the falls - no joke, one wrong step and he would have fallen to his death. It was terrifying for me as a parent - not a place I would want to bring a toddler at all