Original mid-19th century lithograph from the U.S. Pacific Railroad Expedition & Surveys (U.S.P.R.R. Ex. & Surveys), California and Oregon section, Mammals – Plate III. Published ca. 1855, this scientifically detailed print features a weasel (Fig. 1) and a rock squirrel (Fig. 2), drawn by J.H. Richard and lithographed by Hoffman, Knickerbocker & Co., Albany, N.Y., with engraving work by R. Metzeroth. Issued as part of the official government report documenting the flora and fauna encountered along proposed railroad routes through the American West. Printed on heavy wove paper with light age toning and minor edge wear. A fine example of early American natural history illustration.