Dan, here is a page from the Wisconsin DNR with some pictures of wild parsnip that I have invading a pasture:

http://www.dnr.state.wi.us/invasives/photos/index.asp?mode=detail&Code=Passat

It does not appear to be poison hemlock. I think I will try Ben's 2,4DB. This plant does cause an itching rash. There is a lot of it on the roadsides and in neighbors fields. I'll just have to keep after it not let it go to seed but it is tough since it is everywhere. With all the rain we've had pastures and everything are growing. Will really take off if it cools a bit later in the week.

Thank you.

Jim at Dawn