The 1849 publication of his geology of Mount Shasta was undoubtedly a response to the California gold rush publicity. Dana was the pre-eminent U.S. geologist of his time, and he also was one of the few trained observers anywhere who had first-hand knowledge of the northern California terrain. He had previously written that there was a likelihood that gold was to be found all along the route between the Umpqua River in Oregon and the Sacramento Valley. He was probably deluged with inquiries about the Shasta region, and was forced to publish in more detail some advice to the would-be gold miners.