Abstract: A method which relates basin characteristics with peak flow characteristics is presented for determining magnitude and frequency of floods on streams with drainage areas between 0.5 and 200 square miles. Regression equations for each of eight regions are presented for determination of the 10-year flood. Peak flows for the 25- and 50-year floods can then be estimated from ratios developed for each region. Regression equations are not developed because of poor definitions for several areas that total about 20,000 square miles. The equations were based on multiple-regression techniques using annual peaks and basin characteristics for 303 gaged sites.

This report contains data from a survey taken between August 11 and August 27, 1978 on the high sensitivity airborne gamma-ray spectrometer and magnetometer over the Ashton quadrangle in Idaho, Montana, and Wyoming.

Single record data listings taken during aerial gamma-ray and magnetic surveys of the Ashton quadrangle in Idaho, Montana, and Wyoming.

Averaged record data listings taken during aerial gamma-ray and magnetic surveys of the Ashton quadrangle in Idaho, Montana, and Wyoming.