As spring turns to summer, two of the state parks serving Butler County — Moraine and McConnells Mill — are reaching their peak time of year, with more and more events dotting the calendar.

All summer long — McConnells Mill State Park’s historic 19th century grist mill, the centerpiece of the 2,500-acre park, opened for the season Saturday, May 17, and will open for tours Wednesdays through Saturdays throughout the summer from 10:30 a.m. to 3:30 p.m., as well as summer holidays.

May 24 — The Moraine Preservation Fund, the nonprofit organization which supports Moraine State Park, is offering cruises on Lake Arthur aboard the pontoon boat Preston’s Pearl. The first cruise of the season is Saturday, May 24. Tickets can be purchased at the Owlet Gift Shop near the McDanels Boat Launch, or online at the organization’s website.

May 24 — Moraine State Park is hosting a Warbler Walk at 8 a.m., a bird-watching walk focused on finding warblers. Participants will meet at the Old 422 Launch.

May 31 — Moraine State Park is hosting a paddle up Lake Arthur at 9 a.m. hosted by park naturalists. Ages 12 and up are allowed, but those under 18 must be accompanied by an adult. The park can provide a kayak, but due to high demand, sign-ups for park kayaks are limited to two per year. Life jackets are required.

June 9 — Moraine State Park is hosting a “full moon paddle” along Lake Arthur at 8 p.m., which will start during the sunset and take paddlers through the lake during the full moon. Ages 12 and up are allowed, but those under 18 must be accompanied by an adult. The park can provide a kayak, but due to high demand, sign-ups for park kayaks are limited to two per year. Life jackets are required.

June 13 — McConnells Mill invites geology buffs to the “Hell’s Hollow” section of the park at 7 p.m. for a tour led by a park guide who will explain how it got its name, as well as its connection to the iron industry.

June 14 — One Saturday a month during the summer, the Moraine, McConnell's Mill and Jennings Commission offers a “living history” demonstration of the vintage Muddy Creek Oil Well at Moraine State Park. Visitors will get a chance to see the old oil well pump some crude oil as it used to. The demonstration is open from 11 a.m. to 4 p.m.

June 14 to 15 — Moraine State Park is hosting an overnight hiking trip on the Glacier Ridge Trail, starting at 1 p.m. June 14. Participants will meet at the bicycle rental parking lot and hike 4.5 miles to the Davis Hollow Cabin. After a long night’s rest, there will be another 3.5 miles of hiking to the 528 Boat Launch. Pre-registration is required and costs $30. Participants should be prepared for difficult terrain. There is a cap of 12 participants, age 12 and up.

June 24 — Moraine State Park is hosting an educator workshop on the “Wonders of Wetlands” curriculum for kindergarten through 12th grade, which will focus on teaching about wetlands in the classroom. The workshop will take place from 8:30 a.m. to 4 p.m. at Pavilion 7 at the McDanel’s Launch Area on the North Shore. Participants will go on a kayak paddle to learn how to identify wetland plants. Seven Act 48 hours are available. Registration is required.