In a diminutive space in San Francisco’s financial district, the tradition of representing the vast landscape of the American West is extended and reinvigorated by Richard T. Walker and Letha Wilson. The natural and the manmade collide in Walker’s multimedia sculpture the other side of meaning something other than this (2015) and Wilson’s three photo-based wall works. Formally connected through repeated slanted lines and hints of geological forms, the pieces in the exhibition reference the past while operating very much in the present. Tied to conventional art forms like straight photography and landscape painting, the works nevertheless resolutely deny medium specificity through an unorthodox juxtaposition of materials. A glowing white neon tube rises from a bass amplifier, draws the stark outline of a mountain across the gallery window, and returns into a pedestal holding a walkie-talkie balanced on an unremarkable rock that depresses an “A” note on a Casiotone keyboard. A similar, slightly larger rock several feet away is bounded by a thick black cord that stretches up to the ceiling and then hangs down, weighted by an inverted microphone. The rocks, collected in Nevada, connect the mechanical sculpture to the natural environment. The subtle sound enveloping the small room is …