Summertime: A Guide to Entertainment, Activities And Excursions : Head for the Hills : Hundreds of miles of nearby mountain trails provide scenery, flowers, streams and plenty of solitude for hikers.

You don’t have to empty your wallet or your gas tank to escape this area’s traffic, crowds and congestion. Just take a hike.

Hundreds of miles of trails crisscross the Santa Susana, Santa Monica and San Gabriel mountains.

Head for the hills surrounding the San Fernando Valley, and within an hour you can be lunching by a pond, dipping your toes in a stream or enjoying solitude and scenery from a mountaintop.

Here are some trails to get you started:

* O’MELVENY PARK TRAIL to Mission Point: 4 1/2-mile round-trip.

To see the entire Valley in one sweeping view, spend a cool morning or late afternoon climbing to the top of 2,771-foot Mission Peak in the Santa Susana Mountains.

Your hike begins just above Granada Hills at O’Melveny Park. Follow the wide fire road identified by a trail-head sign as the “Dr. Mario de Campos Trail” (it is named for a popular physician who regularly trekked up the mountain until his death in 1984).

Several narrow trails also lead to the peak, but unless you are in the mood for a steep climb, stay on the main road, which ascends gradually.

You won’t find much shade on this hike, but the trail is surrounded by golden and purple fields of wild mustard and lupine during much of the year.

As you climb, look over your shoulders: On a clear day, you’ll be treated to a panoramic view of the San Fernando and Santa Clarita valleys, Los Angeles and surrounding mountain ranges.

To get there: From Rinaldi Street in Granada Hills, head north on Balboa Boulevard. Follow Balboa to Jolette Avenue; turn left on Jolette, left on Sesnon Boulevard and right on Neon Way. Park on Neon and walk to the trail head just beyond the end of the street.

* WILLIAM S. HART COUNTY PARK TRAIL: 2 1/2-mile round-trip.

This easy walk circles William S. Hart Park in Newhall, former estate of the cowboy silent movie star. After your hike, lunch on the grassy picnic area or explore the restored ranch house and museum. Kids will want to pet the animals in the barnyard zoo.

The trail, which begins just past the enclosure of a small buffalo herd, gradually climbs along a dry creek bed. At the crest of the hill, sit on a stone bench and enjoy great views of the Santa Clarita Valley. Soon after you descend, you’ll reach “Heritage Junction,” a cluster of old houses, a one-room schoolhouse, a tiny blue-and-white chapel and the historic Saugus Train Station, all being restored by the Santa Clarita Valley Historical Society.

To get there: William S. Hart County Park is on San Fernando Road and Newhall Avenue. Park near the picnic area on Newhall Avenue. The trail (a fire road marked for equestrian use) is on Market Street just past a senior citizens center.

* MUSCH RANCH TRAIL at Trippet Ranch, Topanga State Park: 4-mile loop.

With 9,000 acres of backcountry hiking trails, Topanga State Park is the nation’s second-largest urban park. Headquarters are at Trippet Ranch, named for Oscar Trippet, a federal judge during President Woodrow Wilson’s administration. Trippet called his rancho Las Lomas Celestiales (The Heavenly Hills).

Several trails begin at Trippet Ranch. Depending on your energy, you can walk a short mile along a self-guiding nature loop or hike almost 10 miles to Will Rogers State Historic Park.

For a moderate workout, plenty of variety and splendid views, try the Musch Ranch trail. You’ll cross a grassy meadow, enter a shady woodland and head into chaparral before arriving at Musch Ranch, where you’ll find a campground, water, restrooms and picnic tables. After this point the trail begins a more difficult climb. When you reach the fire road at Eagle Junction, turn right and head back to Trippet Ranch, enjoying beautiful vistas of Topanga and Santa Ynez canyons.

To get there: From Topanga Canyon take Entrada Road east. Make left turns at every intersection to stay on Entrada. The park’s main entrance is at Trippet Ranch, about a mile from Topanga Canyon. Parking is $5. Trippet Ranch facilities include a picnic area, drinking fountain and restrooms. The Musch Ranch trail head is just past the bulletin board, to the left of the pond.

* BEAR DIVIDE TRAIL: 1-mile loop.

Bear Divide, in the San Gabriel Mountains above Lake View Terrace, offers scenic vistas, picnic facilities and a pleasant, easy walk.

On this hike you’ll see a forest regenerating itself. The trees are scorched and blackened as the result of a 1988 fire, but the trail is notable for wildflowers, especially bush poppies that grow profusely after a fire. These bright yellow blossoms grow on tall shrubs and smell like sweet honeydew melons.

On your way to Bear Divide, you’ll drive past the Wildlife Waystation, an animal rescue center that cares for thousands of injured, abandoned and orphaned animals. Tours are given on the first and third Sunday of every month for a small fee. (Call 818-899-5201 for information.) Farther up the road, stop to inspect the San Gabriel earthquake fault, identified by a sign and short trail.

To get there: Take the Foothill Freeway to Osborne Street in Lake View Terrace. Turn left and continue on Osborne, which soon becomes Little Tujunga Road. Park at the Bear Divide Station, 11 1/2 miles from the freeway. The trail head is immediately next to the parking lot. (At this writing, a sign warns that the trail is closed, but rangers say it’s fine to ignore the sign.)

* WILDWOOD PARK TRAILS: 2 miles to Paradise Falls round-trip, or 5 miles via Lizard Rock and Mesa Trails.

Wildwood Park in Thousand Oaks was the site of many movies and television Westerns. “Wuthering Heights,” “Spartacus” and “The Shores of Iwo Jima,” as well as television series such as “The Rifleman,” “Wagon Train” and “Gunsmoke” were shot here. Today the 1,700-acre park offers waterfalls, large expanses of wildflowers, and a well-maintained, well-marked trail network for hikers of all abilities.

Picnic benches and barbecues are set up under the tree along Wildwood Creek, and signs identifying local flora and fauna are discreetly placed along trails. Despite these obvious civilizing influences, the park is clean, beautiful and serene.

Begin your hike by following the signs to the Nature Center. Examine the plant and animal displays, and ask for a map of the park. Continue walking along Wildwood Creek to Paradise Falls. Wooden stairs lead down to the falls, but no swimming is allowed. For a nice view with little effort, follow the signs to the Teepee Outlook before returning to your car.

If you feel ambitious, try steep Lizard Rock Trail. Enjoy the vistas from 931-high Lizard Rock and return via Mesa Trail.

To get there: From the Ventura Freeway, take the Lynn Road exit in Thousand Oaks. Drive 2 1/2 miles north to Avenida Los Arboles. Turn left and proceed a mile to the park entrance, then drive down the dirt road to parking lot No. 1.