Between 1983 and 1998, CO was monitored at the Horizon Hotel in Stateline, Nevada. In 1999, the monitoring site was relocated to Harvey’s Resort parking garage in Stateline, Nevada. The site is located to monitor the highest CO concentrations in the Lake Tahoe Basin because historically this area received the highest traffic volume, and is intended to be representative of both the California and Nevada sides of the South Shore Resort District. NDEP successfully petitioned the EPA to remove this monitoring site on June 30, 2012 because of the continued compliance with established CO concentration standards. CARB provided TRPA with a CO monitor which was installed on the roof of the TRPA building in Stateline, NV in 2013.