Whiteface Mountain, with an elevation of 1483 m above sea level, is a relatively low mountain by global standards. At the same time, the summit is some 90 m above the tree line and it is the fifth highest peak in the Adirondack Mountain Range of New York State. Whiteface Mountain is set apart from the other Adirondack High Peaks, providing an ideal location for many types of atmospheric measurements. The geographical location in the northeastern U.S., the lone massif character of the mountain, and the fact that the summit is very often enveloped in cloud has made the observatory an attractive place for scientific research. A four story building specifically for the purposes of scientific research and fire monitoring was built on the summit in 1971. The headquarters of the Whiteface Mountain facility, the Marble Mountain Lodge, is perched on the shoulder of the massif at an elevation of 604 m a.s.l. In some cases the same measurements are made at the two locations to explore the two different but geographically close environments. A summary of past and current measurement activity at both locations is presented in the paper along with selected examples of data sets, analyses, and applications. Important research in the areas of forest ecology, cloud water chemistry, precipitation chemistry, reactive trace gases, and airborne particulate matter are reviewed. Collected data sets for temperature and ozone at the summit are presented, as well as research linking the measured gaseous SO2 to acid deposition at this location. In addition, an example is given using this long-term data for both gases and particulate matter that helps to establish the accountability of air pollution regulations in the control of sulfur oxides.