Kids are welcome to run, romp, hike, splash and get dirty during a free day of outdoor play Sept. 12 at Rancho Mark West northeast of Santa Rosa.

Families can gather for a guided exploration of the habitat of the 124-acre ranch. But there will also be time for free play and splashing about in the creek ending with a picnic lunch at noon.

Families who don’t want to hike can hang out in the redwood grove by Mark West Creek. Activities are geared toward kids of all ages although the trails are bumpy for strollers.

Meg Hamill of LandPaths, which is co-sponsoring the event with the Sonoma County Agricultural Preservation & Open Space District, will lead the activities and will come equipped with gear for amateur explorers, including insect nets, magnifiers and nature ID guides.

Registration is required at Rancho Mark West is at 7125 St. Helena Road, which is about 2.6 miles off Calistoga Road.

You can reach Staff Writer Meg McConahey at or 521-5204. On Twitter @megmcconahey.