About a mile in, the trail splits, and I decided to wander the "nature path" which was much narrower (compared to the wide-open ski trails) and gave me a bit of a better workout.
A half mile after that, the nature trail rejoins the wide open loops. My time cut short, I beelined for the observatory tower to snap a few pictures from the top.
Another mile and a half later, I was back at my car and on the road... a little over an hour, 3 miles of walking, and happy I'd gotten outside.
There are quite a few loop trails in the park, ranging from 2.5 miles up to a 5 mile loop. A portion of the Ice Age Trail also runs through the park (and overlaps these loops).