as for the plant (poison oak & poison sumac too), it's becoming stronger than it has been thanks to climate change.
Poison ivy, poison oak and poison sumac plants are becoming larger and stronger, a trend that's been developing over recent years, according to researchers. That may be a combination of the plant's nature to cause more severe reactions over time and the increased carbon dioxide in the atmosphere as a result of global warming.
and the oil can stay on clothes & lawn equipment for 5 years!
apparently the best way to get rid of it it, if you don't want to dump a bunch of herbicide on it, is to get (or even rent) a few goats, they love the stuff. although, they just eat the plant, the roots are still there & will grow again so if you rent, you'll have to do it more than once for them to eat the leaves off often enough so the roots have no energy to grow again.