Carbon Canyon Regional Park, one of the many smaller units of Orange County�s far-flung regional park system, has enough room for one significant hiking trail. An unlikely grove of coast redwood trees, nursed from seedlings and planted in 1975, lies at the end of this self-guiding nature trail. Indigenous to the California coast only as far south as Monterey County, their survival in this rather dry corner of Orange County is quite remarkable.
Carbon Canyon Regional Park is located just east of the city of Brea, one mile east of Valencia Avenue, on Carbon Canyon Road. A small fee is collected for parking here. Summer hours are 7 a.m. to 9 p.m. This typical suburban recreational facility features various sports facilities, picnic grounds, and pedestrian/bike paths. The entire park lies within the flood zone of the Carbon Canyon flood-control dam, which someday may protect urbanized areas downstream at the expense of inundating the park. The park also happens to lie squarely within the Whittier fault zone, a major splinter of the San Andreas Fault.
The park�s nature trail begins just east of the park�s entrance. Follow the designated path through a grove of planted pines and down into the bed of Carbon Canyon. The tiny stream is flanked by a variety of water-loving plants: the native mule fat and willow and the nonnative �giant reed,� a naturalized exotic plant resembling bamboo. The reeds tend to compete with native plants for water and are the target of eradication programs here and all over San Diego County as well.
After what could be a muddy creek crossing, a trail on the left leads east across a grassy terrace toward Telegraph Canyon in adjoining Chino Hills State Park. Stay right. The nature trail continues west, hugging a dry hillside on the left and dense riparian vegetation on the right. Graceful native walnut trees and nonnative pepper trees can be seen along the hillside, along with nonnative fennel, mustard, and castor bean. The trail bends left into an arm of the basin just above Carbon Canyon dam. Here you find the curious stand of redwoods, a picnic bench, and a drinking fountain. Subsurface water in the basin may keep these redwoods alive, but without the rain and fog drip they are accustomed to in their native habitat, they look a bit thin and dusty.