Celebrate Earth Day from 10 a.m.-2 p.m. at the new Nature’s Classroom Institute property, W335 S8301 County Road E, Mukwonago. This event, hosted by Nature’s Classroom Institute & Montessori School in collaboration with the Friends of the Mukwonago River, will feature nature hikes, invasive species removal demonstration, children’s activities, tree planting, rain barrel painting and auction, cookout lunch and more. Cost to attend the event is $5. All proceeds will be used to purchase trees to be planted on the new property and help with other ecological restoration expenses. To register, click here. For more information, call (262) 363-6820.