The monarchs in northern California are substantially more abundant this year so I think you will see even more monarch activity in late July and early August when alot of our California butterflies that are currently in the caterpillar and chrysalid stage emerge and wander into Oregon.
I saw this caterpillar yesturday on speciosa milkweed about 50 miles east of Sacramento at about 1,900 feet elevation:
http://www.youtube.com/watch?v=cWlTz0cKwfgAnd today I saw this adult patrolling fascicularis milkweed about 20 miles east of Sacramento at about 900 feet elevation:
http://www.youtube.com/watch?v=OntA3OhJhzw