Carrie Caudle, a kindergarten and first grade teacher at Mary Collins School at Cherry Valley in Petaluma, gathered her wide-eyed kids for a quick rules briefing before turning them loose to the wonders of the Tolay Fall Festival.

"Let's go get our pumpkins. What do you think?" she said.

"Yay!" cheered the youngsters decked out in matching orange T-shirts.

More than a pumpkin patch, the annual fall festival is an educational experience, Caudle said.

"There's something for everyone," she said. "It's about seasonal change and the history of the land and the people. The kids get a lot out of it. As you can see, they're excited to be here."

In its eighth year as a Sonoma County Regional Parks event, the two-week festival is expected to draw 20,000 visitors to Tolay Lake Regional Park southeast of Petaluma, said Brandon Bredo, a park ranger and event organizer.

"We get to showcase Sonoma County's finest," he said. "We're showing kids the way the land used to be. It's very ag and environmentally focused."

The festival, which is open only to school groups during the week, will be open to the public Saturday and Sunday from 11 a.m. to 5 p.m. Admission is $4 for adults and $1 for kids aged 12 or younger. Parking is $7.

More than 1,300 Bay Areas students ran through the hay bale maze Thursday and bounced along on tractor rides. They made crafts out of corn husks and spun wool. They gaped at "creepy crawly" creatures like tarantulas, snakes and scorpions. And they explored Native American culture at the Miwok and Pomo replica village.

"We're giving the students a little sample of indigenous culture," said Edward Willie, a Pomo from Mendocino, as he built a traditional dwelling out of tule reeds called a kotcha.

The area was once a gathering spot for Native Americans from across California who came to cast charm stones into a seasonal lake to cure illnesses.

Today, the 1,769-acre park contains pristine farm and grasslands, ponds, wetlands and ridges that provide views of San Francisco Bay and the Petaluma River. Outside of the festival, park access is allowed through day-use permits and guided hikes. The next scheduled hike is Oct. 27.

On Thursday, Rowan Hamner, a Cherry Valley first-grader, showed off a corn husk doll she made at the craft booth. "The best part was you get to make dolls," said Hamner, 6. "I made it with corn!"

Mickey Huff, father of first-grader Molly, said the festival is a family friendly event. "As a parent, it's a cool place to bring a kid."

An old barn on the property once hosted a haunted house when the previous land owners, the Cardoza family, ran a commercial pumpkin patch. Now it's home to the hands-on animal display, including some critters known to raise some Halloween goosebumps.

"In the creepy crawly room, kids get a creepy Halloween experience," said ranger Matt Reid. "Then we focus on education and learning to not be afraid but appreciate these animals."

The creepier the better, said Danny Garrison, 6, of Petaluma as he gazed into a vivarium full of 100 wriggling baby rattle snakes.

"I like all the animals," Garrison said. "I like when it's scary and stuff."

(You can reach Staff Writer Matt Brown at 521-5206 or matt.brown@pressdemocrat.com.)