Definition: The Black Rock is a conspicuous volcanic feature rising above the flat plain of the Black Rock Desert playa. It was first described by Frémont in 1844, and subsequently used as a landmark by emigrants headed for Oregon and California on the Applegate-Lassen Trail. The annual Burning Man festival is held on the Black Rock playa. A large area around the desert is public land administered as the Black Rock Desert High Rock Canyon Emigrant Trails National Conservation Area.
Examples:The Black Rock Desert playa is one of the flattest places on earth.