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.
Sunset breaks through a snow squall revealing Yosemite's Cathedral Spires on a cold February afternoon. Yosemite Valley is a glacial valley in Yosemite National Park in the western Sierra Nevada mountains of Central California. The valley is about 7.5 miles (12 km) long and approximately 3000-3500 feet deep, surrounded by high granite summits such as Half Dome and El Capitan, and densely forested with pines. The valley is drained by the Merced River, and a multitude of streams and waterfalls flow into it, including Tenaya, Illilouette, Yosemite and Bridalveil Creeks. Yosemite Falls is the highest waterfall in North America, and is a big attraction especially in the spring when the water flow is at its peak. The valley is renowned for its natural environment, and is regarded as the centerpiece of Yosemite National Park, attracting visitors from around the world.