For the past three years, a herpetofaunal study of an ecological transect through the eastern front range of the Sierra Madre Oriental has been conducted in the Mexican states of San Luis Potosi and Queritaro. The transect passes through tropical deciduous, semi-cloud, pine-oak, dry oak and desert scrub forests within the first 65 kilometers, transversing elevations from 90 to 2,550 m. Brief descriptions of the various major vegetational areas are included. Sixty-five new herpetofaunal records are listed for the state of Queretaro. A discussion of systematic problems includes the species Pseudoeurycea cephalica, Sceloporus jarrovi, Eumeces lynze, E. tetragrammus, Lepidophyma flavimaculatum, L. gaigeae, and L. smithi. A vast amount of information on the distribution and systematics of Mexican reptiles and amphibians has accumulated over the past 20 years, or since the last publication of the Smith and Taylor (1945, 1948, 1950) checklists on the herpetofauna of Mexico. During this surge of interest, large amounts of data were accumulated on various aspects of the biology of families, genera and species, including specific studies on their distribution within political boundaries of Mexico. Smith and Taylor (1945, 1948, 1950) included state lists in each of their publications, and some major contributors to specific state and regional studies were Alvarez del Toro (1960); Bogert and Oliver (1945); Davis and Dixon (1959, 1961, 1965); Davis and Smith (1953a, 1953b, 1953c); Duellman (1958, 1960a, 1961, 1965a, 1965b); Hardy and McDiarmid (1969); Martin (1958); Schmidt (1922); and Taylor (1949, 1952, 1953). In general, there are several hundred assorted notes and short papers on range extensions, systematics, ecology and morphology of Mexican amphibians and reptiles. Specific locality records of amphibians and reptiles for Queretaro are given by Altig (1964); Chrapliwy (1964); Dixon and Ketchersid (1969); Duellman (1960b, 1970); Klauber (1952); Lynch (1970); Martin del Campo (1936); Rabb (1965); Smith (1942); Smith and Brandon (1968); Smith and Taylor (1945, 1948, 1950); Webb (1968); and Zweifel (1956).