Before they learned how to produce metal, people throughout the world made tools out of stone.

Some experienced stone toolmakers will demonstrate this ancient skill at a "knap-in" on Saturday and Sunday, Aug. 25 and 26 at Coyote Hills Regional Park in Fremont.

Knapping has nothing to do with sleep. During informal sessions from 10 a.m. to 3 p.m. each day at the visitor center, you can learn how chert, obsidian and other stones were knapped (shaped by striking) into spear points, arrowheads and drills. The center also has great exhibits highlighting the cultures of Central California Indians and the local Ohlone Indians, who have inhabited the region for millennia.

Young children may watch the knapping process; anyone 13 years or older may give knapping a try. If you want to do it, bring leather gloves and protective eye wear.

Coyote Hills is at 8000 Patterson Ranch Road. There's a parking fee of $5 per vehicle. The "knap-in" is free of charge. For information, call 510-544-3220.

WILDERNESS MOON: At Sunol Regional Wilderness, naturalist Katie Colbert has scheduled a wilderness moon hike from 6:30 to 10 p.m. on Saturday, Aug. 25 as part of her Women on Common Ground series.

It's for women who enjoy outdoor activities, but have concerns for personal safety. This one is a three-mile round trip to Sunol's High Valley via the Indian Joe Wilson Trail, with some steep sections. The group will gaze at the moon and stars

It's free, but reservations are required. Call 888-327-2757. Select option 2 and refer to program 30029.

DEL VALLE HIKE: Join a campfire program from 9 to 10 p.m. this Saturday at Del Valle Regional Park south of Livermore. It's at the park's campground, but non-campers are welcome. Children must be accompanied by an adult.

The topic will be astronomy. Find out why the year 2012 is important to the traditional Mayan calendar, and pick out summer constellations as you duck the falling stars of the weekend's Perseid meteor shower. Bundle up and bring a blanket to lie on after dark.

Del Valle is at the end of Del Valle Road off Mines Road, about nine miles south of Livermore. There's a fee of $6 per vehicle at the entrance kiosk. Park by the campground store. For information, call 510-544-3249.

brushy peak: For an evening activity without campfire, join naturalist Trent Pearce on a two-mile stroll from 7 to 9 p.m. Tuesday at Brushy Peak Regional Preserve in Livermore. With luck you may hear owls, frogs and other denizens of the dark.

It's free of charge, part of the park district's Tuesday Twilight series. Meet at the end of Laughlin Road just north of Interstate 580. For information, call 510-544-3285.

SNAKES: Naturalist Bob Kanagaki likes to take road trips with reptilian companions. He's bringing his snake show to Martinez Regional Shoreline from 10 to 11:30 a.m. this Saturday.

If you'd like to learn more about Bob's captive snakes and their wild cousins, meet him at the picnic area near the park's North Court Street parking lot, just over the railroad tracks from downtown Martinez. For information, call 888-327-2757, ext. 2750.

TAKE THE DOG: Your dog might enjoy a walk with you in shady, scenic Redwood Regional Park in Oakland. If you think so, bring the pooch and join naturalist Kristina Parkison there this Sunday, for a hike from 9 a.m. to 2 p.m.

Kristina will provide homemade dog snacks. People should bring a picnic lunch.

The hike is designed for ages 8 and older (people, that is). It's free, but registration is required. For registration and directions, call 888-327-2757. Select option 2 and refer to program 30056.

Ned MacKay writes a regular column about East Bay Regional Park District sites and activities. Email him at nedmackay@comcast.net.