Yes, that’s a good site. It can take a long time to load that map but you can ignore the map and still see the rest of the information.
I have found that poison oak is largely manageable with full-length clothing and the ability to identify it so easily you can ID it with your peripheral vision. If you do come in contact with it, wash the area immediately even just with some plain cold water. After the hike, put your laundry in the wash before you shower.
In the end, for the vast majority of people, poison oak is just a rash. It is not death, it’s not an illness, it’s just annoying. If you are one of the few who will die from it, disregard the previous sentence and move on from this post. I find that most people are unduly frightened by poison oak and that friends of mine who get it easily and severely would rather enjoy the backcountry and deal with the rash than stay home.