Tuesdays without Fail

If it’s a Tuesday, you can be sure that a park employee or volunteer is on their way to check one of the two National Acid Deposition Network (NADP) sites in the park. These sites, part of a nation-wide system of 220 collection points, monitors trends in the nation’s “chemical climate.”

The NADP network has it’s origins back in the late 1970’s when acid rain emerged as a growing environmental concern in the United States. Acid rain, characterized by elevated levels of hydrogen ions, is more chemically reactive than normal rain. The extra ions can cause corrosion of buildings, influence soil chemistry, and affect the health of crops. Acid conditions are particularly damaging to aquatic life. In addition to acidity, NADP sites provide information on sulfate, nitrate, ammonia, and chloride deposition, chemicals that also influence soil and water chemistry. The large network of sites contributes to a comprehensive understanding of deposition and trends. Rainfall is monitored at each site as this is important for making comparisons between sites.

One park NAPD sampling site is near a road and is relatively easy to access. The other site is tucked away in a mountain valley almost three miles and 1,000 feet in elevation gain up a trail. Nevertheless, despite windy, cold, or snowy conditions, collection of the sampling bucket happens on Tuesdays. The person “on duty” follows a strict protocol to ensure the sample is uncontaminated by oils from their hands or dust during transport. Samples are shipped to Illinois for analysis.

For more about the NADP network, or to access sampling data, visit the system’s web site.

Last updated: March 31, 2012

Contact the Park

Mailing Address:

1000 US Hwy 36
Estes Park, CO 80517


(970) 586-1206
Through winter, the Information Office is open 8:00 am–4:30 pm Mon–Fri. Recorded Trail Ridge Road status: (970) 586-1222.

Contact Us