After HOK's Oriole Park at Camden Yards in Baltimore won the architectural World Series, that Kansas City firm's Joseph Spear and Bradley Schrock designed a second old-fashioned-looking ball park for the Colorado Rockies, a National League expansion team established in 1993. The four-story curved brick entry has a clock cornice flying the flag in a salute to traditional baseball parks such as Brooklyn's Ebbbets Field. The red brick walls relate to the surrounding warehouse district and incorporate one old building. Coors Field combines high-tech modernism with nostalgic elements such as a grass playing field, a hand-operated scoreboard, and “knothole” peeps at the field through the main (20th and Blake sts.) entrance. Brick pilasters are topped by forty terracotta columbines (the Colorado state flower) by Denver sculptor Barry Rose. Another piece of public art is the gleeful sculpture Evolution of the Ball (1995, Lonnie Hanzon), a large psychedelic baseball on a stretch of tilted railroad track supported by columns with 108 glazed terracotta balls, ranging from mud balls to cheese balls. The entire stadium is sunken behind red brick walls no higher than 60 feet to minimize obstacles to mountain and city views.