Back in September 1775, a Spanish officer named Juan Bautista de Anza led a multi-ethnic contingent of soldiers, friars and colonists on a months'-long overland trek from northern Mexico and present-day Arizona to the mission settlements in California.

After a long and sometimes arduous journey, the group reached Monterey in March of 1776. From there, de Anza led a smaller party north to explore what are now San Francisco and the East Bay. They traveled as far as present-day Antioch.

Commemorating their journey more than two centuries later, East Bay Regional Park District naturalists will host free programs on April 7 at points along de Anza's route, highlighting both his experience and the Native American cultures he encountered along the way.

First is a program from 10 a.m. to 1 p.m. at Contra Loma Regional Park in Antioch. Meet at the park's de Anza information panel just past the park entrance kiosk to see how the Indians used soaproot and made brushes from the plant. The park is at the end of Frederickson Lane off Golf Course Road. There's a parking fee of $5 per vehicle. For details call 888-327-2757, ext. 2750.

Ohlone Indian food and folkways will be showcased in a program from 11 a.m. to 4 p.m. at Dry Creek Pioneer Regional Park in Hayward, led by three generations of Ohlone/Bay Miwoks. Meet at the de Anza information panel by the parking lot at May Road and Mission Boulevard in Hayward.

And from 1 to 5 p.m. April 7, naturalist Michael Charnofsky will lead a car caravan from Mission San Jose to Oakland, retracing the Anza trail and stopping at four historically important points along the way.

Registration is required for Michael's program. To register, call 888-327-2757, select option 2 and refer to program number 1552. For details on Michael's program, call 510-544-3183. For more expedition information, visit www.ebparks.org/activities/naturalists/anzahistoric.

POTPOURRI: Dog walkers will enjoy "Canine Capers," a dog-friendly hike from 9 a.m. to 3 p.m. March 30 at Pleasanton Ridge Regional Park near Pleasanton, led by naturalist Kristina Parkison (course number 1500). It's for ages 8 and older (people, that is) and registration is required.

On March 30, Cat will lead a 2.5-mile springtime hike to the Little Yosemite area of Sunol from 8 to 10:45 a.m. to view wildflowers and talk about the Calaveras dam project. Steep in places, the hike is for ages 7 and older. It's course number 1597.

Then on Easter Sunday, March 31, Cat will lead a strenuous but slow-paced hike to the top of Sunol's Flag Hill, from 8 to 11:45 a.m. (course 1634). This one's for ages 9 and older.

All these south county programs are free, except for parking fees, and registration is required. For registration and information, call 888-327-2757, select option 2, and mention the program course number, name and date. Or register online at www.ebparksonline.org.

BUNNY TALK: Scientifically speaking, rabbits are members of an animal order called lagomorphs. Interpretive student aide Morgan Rani Evans will host a "lagomorphs on the lawn" program from 2 to 3 p.m. Sunday, March 31, at the Environmental Education Center, sort of a meet and greet with Tilden's resident rabbits. She'll read some stories and share a snack with the bunnies.