This is set just outside of the Historical Complex in McKinley Park along the hike/bike trail. It's about a tenth of a mile walk or less in any direction. Using the parking coordinates included, you'll be closest to the cache.
You're looking for a small box with a log and some swag. Bring your own pencil. If you come on a Saturday or Sunday, the Historical Complex is open from 1:00 to 4:30 pm. Check it out.