The California Field Atlas is a 2017 book written and illustrated by Obi Kaufmann. It was published by Heyday Books, a Berkeley-based nonprofit small press. Through passages of nature writing and hundreds of watercolor paintings, the book details California's ecology and geography. Kaufmann, an artist and outdoorsman, was born in California and currently resides in Oakland. He prepared the book over the course of a year, drawing from a lifetime of experience hiking thousands of miles of California wilderness. With the California Field Atlas, he intended to foster geological literacy and conservation of the state's natural environment.