Sunset on Mono Lake
Tufa, the rock formations that "grow" in Mono Lake, is essentially common limestone. What is uncommon about this limestone is the way it forms. Typically, underwater springs rich in calcium (the stuff in your bones) mix with lakewater rich in carbonates (the stuff in baking soda). As the calcium comes in contact with carbonates in the lake, a chemical reaction occurs resulting in calcium carbonate--limestone. The calcium carbonate precipitates (settles out of solution as a solid) around the spring, and over the course of decades to centuries, a tufa tower will grow. Tufa towers grow exclusively underwater, and some grow to heights of over 30 feet. The reason visitors see so much tufa around Mono Lake today is because the lake level fell dramatically after water diversions began in 1941.

Big Sky Country
Low tide at sunset on Dog Beach in Ocean Beach, San Diego.

Dog Beach, Ocean Beach
Dog caught in silhouette at sunset on Dog Beach in Ocean Beach, San Diego--"where dogs rule".

Fiery Sunset
Smoke wafts during the wildfires in San Diego County in 2007, giving a thick haze and dimension to the sun's descent.

Dog Beach--where dogs rule
A Boston terrier caught during sunset at Dog Beach in Ocean Beach, San Diego--"where dogs rule!"

Sunset stabs the valley
A last bit of sunlight stabs the foggy view of Yosemite Valley.

Between storms
Sunset on the beach between rainstorms in Ocean Beach, San Diego.