Map shows cities, towns, and geography of the southwest United States during the early twentieth century. Relief shown by hachures. Scale [ca. 1: 6,336,000] and [ca. 1:8,448,000].

This report discusses the cultivation of bur clover, which is an annual legume that serves as a winter cover crop and as pasturage. The best practices for and uses of bur clover are discussed in detail.

From Introduction: "Technical Paper 66 deals with the mud-laden fluid process in general and No. 68 with its application in Oklahoma. Rather than reprint these publications, it has been considered advisable to replace them with the present report, which includes the results of more recent investigations. The methods of using mud-laden fluid are an outgrowth of the rotary drilling system, which was developed in Texas and later employed in Louisiana and California."