The information in this booklet was compiled to answer inquiries received by the U.S. Geological Survey from students, teachers, writers, editors, publishers of encyclopedias, almanacs, and other reference books, and people in many other fields of work.
The elevations of features and distances between points in the United States were determined from surveys and topographic maps of the U.S. Geological Survey or obtained from other sources. In most cases, the elevations were determined from surveys and from 1:24,000- and 1:25,000-scale, 7.5-minute topographic quadrangle maps. In Alaska, information was taken from 1:63,360-scale, 15-minute topographic quadrangle maps. In a few cases, data were obtained from older, 1:62,500-scale, 15-minute maps; these maps have been replaced with larger scale 7.5-minute coverage.
Further information about U.S. Geological Survey products can be obtained from: U.S. Geological Survey, Earth Science Information Center, 507 National Center, Reston, VA 20192 or phone 1-888-ASK-USGS, E-mail: ask@usgs.gov, TTY: 703-648-4119.
