Atmospheric mercury (Hg), an airborne heavy metal, can be deposited into aquatic and terrestrial systems, posing a risk to ecosystems and human health. It is therefore important to understand the sources, chemical cycling, and fate of atmospheric mercury. This study looks at total gaseous Hg (TGM) and total Hg (THg) concentrations collected at an urban near-road site in Colorado Springs, CO from June - August, 2016 and at a rural location in Rocky Flats National Wildlife Refuge, Louisville, CO, from June - August, 2018. Mercury concentrations at the two sites were significantly different from one another. The urban data set reveals a significant diurnal pattern, with hourly average TGM concentrations reaching a maximum at 3:00 MST (1.9 ± 0.3 ng/m3) and minimum at 13:00 MST (1.6 ± 0.2 ng/m3). In contrast, at the rural site we find that hourly-average concentrations peak at 13:00 MST (1.5 ± 0.1 ng/m3) and are lowest at 6:00 MST (1.4 ± 0.1 ng/m3). These diurnal Hg patterns are comparable to those found in other studies looking at urban/rural differences. Sources of Hg at both sites were also investigated. At the urban site, the data points to high TGM concentrations originating from local sources. Additionally, strong correlation between TGM and CO2 suggests soil evasion as a potential Hg source. The rural site, on the other hand, does not appear to be influenced by nearby Hg point sources and reflects a typical background site.