The expansion of the Colorado Convention Center to its current configuration opened in December 2004. This photo looking down California Street from 16th was taken on May 10, 2004 and shows part of the center’s distinctive 14th Street atrium under construction. To the left, the old Bank of Denver and Republic Hotel buildings on Block 162 are still standing. They would be demolished in August and September of 2007.
For more, check this post on the history of the Colorado Convention Center.