Architect Lester Jones, of a Boulder firm, used a Usonian design for this low-slung courthouse spreading across a full-block site. The asymmetrical plan has single-story wings extending east and southwest from a central two-story core. A relief diamond pattern in weathered copper covers the battered second-story walls, with small, narrow clerestory windows under canopies of the same copper with triangle patterns. Copper fascia trim also edges wall panels, spandrels, and the overhanging flat roofs of the wings. First-Floor walls, capped and edged in smooth limestone, are paneled in irregular slabs cut from amorphous volcanic rock. The main entrance is through a glass curtain wall divided by slab columns. The deep-set doors have vertical full-height glazing paired with geometric-relief oak panels and hardware in triangular shapes. The exterior stone walls continue into the lobby, where an open stairway above a rock garden leads to the second-floor courtrooms.