This years civil war reenactment is September 21 & 22nd beginning at 9 am each day. It is at Milo McIver State Park on S. Springwater Rd. I have attended a few times before and am going Saturday. i find it interesting and the people who do it live, act, and dress just as they would have done back in the time.
It is very interesting. Adults $8; ages 55+ and students with ID are $5;
Here is the link to the information.
I always take Redland Rd. in Oregon City all the way to Springwater Rd., turn right, then go almost 1 mile to the entrance to the park on the left. The event is usually all the way to the last parking lot area.