[en] In 1953, the Environmental Measurements Laboratory (formerly the Health and Safety Laboratory, then part of the USAEC) began a systematic program to measure ⁹⁰Sr in soil through a cooperative effort with the US Department of Agriculture's Soil Conservation Service at its Beltsville Soil Laboratory in Maryland. This effort marked the beginning of the Laboratory's use of soil sampling to study radionuclide deposition that would continue to the present time. As recently as 1986, samples were collected in 11 locations in Europe to study fallout following the Chernobyl nuclear reactor accident. In the 35 years since the first samples were collected, nearly 5000 soil samples have been collected and analyzed. Since these soil samples represent a valuable resource for the chronological study of natural fallout radionuclides and other pollutants in the environment, we have undertaken to catalogue them. These samples represent one of several types of natural matrix samples which comprise the Laboratory's Samples Archive. There are currently a total of nearly 50,000 samples in the archive, including lake sediments, atmospheric dust, seawater, bone ash, and diet ash samples. This report is comprised of two sections, Section 1 describes the inventory database and access system, and the samples available in the archive. In Section 2, Historic Overview, a short discussion for each of the various soil sampling programs is presented. 74 refs