Sunset on Rodeo Beach, located in the Fort Cronkhite area of the Marin Headlands, one of the most special places in the Golden Gate National Recreation Area with access to multiple trails, fantastic views, a dog-friendly beach, fascinating geology, and an interesting history. As a pocket beach, Rodeo Beach sands do not migrate up or down the coast. Instead, they are carried a short distance offshore in winter, tumble about in the surf, and then return to replenish the beach in the spring and summer. Thus, the sands of Rodeo Beach are native to the Marin Headlands and reflect the Franciscan geology of the closest hills and cliffs. This earthcache focuses on the abundant radiolarian chert and rare carnelian pebbles.
The name Joshua tree was given by a group of Mormon settlers who crossed the Mojave Desert in the mid-19th century. The tree's unique shape reminded them of a Biblical story in which Joshua reaches his hands up to the sky in prayer. Joshua trees are fast growers for the desert; new seedlings may grow at an average rate of 7.6 cm (3.0 in) per year in their first ten years, then only about 3.8 cm (1.5 in) per year. The trunk consists of thousands of small fibers and lacks annual growth rings, making it difficult to determine the tree's age. This tree has a top-heavy branch system, but also what has been described as a "deep and extensive" root system, with roots reaching up to 11 m (36 ft). If it survives the rigors of the desert, it can live for hundreds of years; some specimens survive a thousand years.
