Tuberculosis (TB) Tuberculosis (TB) Active tuberculosis (TB) is very contagious. The World Health Organization (WHO) estimates that one-third of the world's population is infected with the bacteria that cause TB.
With an average elevation of 6,800 feet, Colorado is the highest state in the United States. A mountain lake outside of the skiers dreamland of Aspen, Colorado. The US is bordered to the north by Canada and Mexico to the South. With 50 states of varied sizes, US is considered the largest nation in America.
A person in the United States is anywhere between 282 feet below sea level in Death Valley, Calif., and 20,320 feet above sea level in Mount McKinley, Alaska. MySeaLevel.com allows visitors to enter a ZIP code or physical address for the precise sea level of that location.