SWIHE (http://www.swihe.org/) is the SouthWestern Indiana Home Educators, which lists 11 groups under the "Coops and Support Groups" menu on the main page. SWIHE is open to all homeschoolers, but steering committee members share a statement of faith (linked)
Hi, one of my close friends is very involved in a large homeschool co op. if you email me, I can give her your contact info. From what I know, it's a very involved, thriving group!
My name is Anne. You can contact me at
I don't know of specific groups, but there are many families who homeschool in the Newburgh, IN area. You can contact me directly at firstname.lastname@example.org or (812) 629-6930 if you have any other questions about Newburgh.