The Maryland Department of the Environment and the University of Maryland Center for Environmental Science have opened a new air monitoring site in 2004 called "Piney Run". Piney Run is uniquely situated for measuring regional background pollutant loads from a high elevation, western boundary location in rural Maryland. Particulate, aerosol, and haze-related measurements will be collected to better understand the influence of regional pollutant transport into Maryland. Upper air meteorological information is also being collected as part of this effort. Piney Run is part of the Rural Aerosol Intensive Network (RAIN) deployed in Spring 2004 by state agencies in the Mid-Atlantic/Northeast Visibility Union (MANE-VU).