A Cloudless Walk by Randall Couch   Since he first came to public notice with works like “A Line Made by Walking” (1967), British artist Richard Long’s practice has often been characterized as “conceptual.” Coming of age in the era of the “dematerialization of the art object,”1 he was one of many influenced by John Cage, and he showed with self-described conceptual artists like Lawrence Weiner—but he also exhibited in important group shows of earth art, post-minimalism, process art, and arte povera. His work has remained both remarkably consistent and remarkably relevant over more than four decades, while conceptual art in the strict sense can now be seen as a movement pervasively influential, but of its time. Long has said of his practice, “My…