Diamond Lake Park in Montezuma has a 3.7 mile trail that loops around the lake. My kids' favorite part of today's hike was exploring the rocks and fossils, which my husband and his friend really enjoyed too (both are scientists).
The park has a small playground, many lakeside picnic tables and restrooms throughout the park, however every restroom is still closed for the season. The gate to the northern road through the park is still closed as well.
Update: The restrooms opened April 14, 2023 and the northern road opened April 21, 2023.