If you walked the loop the same way as me you are almost back to the parking lot.
You are looking for a small green container - like a preform tube up a small maple tree.
ODNR Permit EF-04-14-24
See https://coord.info/GCARY9Y for parking and trailhead info
Here's a great park map https://drive.google.com/file/d/1vN-M0wnOxctzyuZbwmqZ-M6wVak81Z9Z/view?usp=sharing