When Horace Greeley went to heaven, he must have gotten turned around. At least when California artists hear his spirit prompting them to go in search of opportunity, that’s what he tells them. Susan Magnus is the latest Bay Area artist to decamp for New York, and she’s made getting there from here the subject of her show at the Mills Museum. One highlight: a wall-size print of the U.S. map, displayed with a full pencil cup so that viewers can tell her where to go on her journey east. Through February 15.