U.S. pedon data on the CAPS Version 1.0 CD-ROM, June 1998, are a sample of the pedon data contained on a CD-ROM produced by the National Soil Survey Center - Soil Survey Laboratory(NSSC-SSL). The data include recent pedons from analyses for soil characterization and research within the National Cooperative Soil Survey. Less-than-complete characterization data are available for many pedons because only selected measurements were planned or because the planned measurements are not yet complete. This database is dynamic-- data for additional pedons are added as they are sampled and analyzed, other information is updated as pedons are classified, suspect measurements are rerun and replaced, and errors are found and corrected. The data on the NSSC-SSL CD-ROM represent a 'snapshot' of the database. The database includes pedons that represent the central concept of a soil series, pedons that represent the central concept of a map unit but not of a series, and pedons sampled to bracket a range of properties within a series or landscape. Thus, attribute data for some data elements may be incomplete or missing for certain portions of the United States. In instances where data are unavailable, a mask should be used to exclude the area from the analysis. For research purposes, all data are retained in the database. Users unfamiliar with a given soil or set of data may want to consult with a research soil scientist at the National Soil Survey Center. A research soil scientist can be reached by telephone at (402) 437-5006, or by writing the Soil Survey Laboratory Head, National Soil Survey Center, Natural Resources Conservation Service, Federal Building, Room 152, 100 Centennial Mall North, Lincoln, NE 68508-3866 USA. Pedons on the CAPS Version 1.0 CD-ROM cover areas in Russia (60 deg 37 min N to 69 deg 27 min N; 159 deg 07 min E to 161 deg 33 minE) and in Alaska (62 deg to 68 deg N; 135 deg to 149 deg W).