Table 1. Matched high and low altitude county demographics.

Low Elevation (n = 58)	Elevation (m)	Population	Density (persons/mile2)
Maximum	903	485,493	775
Minimum	0	654	0.51
Mean	366	31,398	37.6
High Elevation (n = 58)
Maximum	3,425	582,881	762
Minimum	2,141	728	0.5
Mean	2,536	38,603	37.3