This paper presents the fractional composition of soil lost from wind erosion for a 45-yr period on mesquite sand dune rangeland in south central New Mexico. In addition, an equation was developed for defining the soil loss by particle size. Three arbitrarily chosen groups (deposition, noneroded, and eroded) were used to categorize the sampling locations. Net soil loss was in excess of 4.6 cm/ha. Maximum deposition was 78.6 cm and maximum erosion was in excess of 61.9 cm. The sand fraction was divided into three particle size classes. There was a significantly greater amount of the 0.5- to 0.05-mm sand fraction in the deposition site than in either the eroded or non-eroded sites. No net loss of sand from the experimental site was measured. The silt fraction was significantly greater in the noneroded and eroded sites than in the deposition site, indicating removal of the silt fraction by wind erosion. Wind erosion occurring on the site is resulting in a more sandy textured soil.