I found this area listed in the AAA Guide to Winter Fun in Michigan printed in The Cass City Chronicle on Feb. 3, 1966. It said Jack Pine Valley had 3 slopes with rope tows, and snowmaking. The map places it a bit north of Port Huron in the same general area where Black Forest is sometimes shown (Black Forest is not mentioned in this list). I have not yet found any other references to Jack Pine Valley. But sources say Jack Pine Valley was later known as Circle-TNT.
Lynn Barrett sent along this Bing link to an aerial view and map of the current condition of the site of Jack Pine Valley–TNT. The area was just east of the Black river, about 1 mi west of the town of Blaine, which is about ten miles NNW of Port Huron.
If you have any information about skiing here or elsewhere in the Port Huron area, please post it in a comment, or send it to us via the directions on the About MILSAP page.