Desert X is a sprawling, site-specific exhibit of 19 art installations dotted across a 50-mile stretch from Palm Springs to the Salton Sea. It incorporates work in many media — from sculpture to digital art to augmented reality pieces. Using the Desert X mobile app, visitors can follow an interactive map and tune in to an accompanying podcast, which features interviews with each artist. John Horn visited the exhibit recently and spoke with the artist Mary Kelly and with co-curator Matthew Schum. Desert X runs through April 21.