The first portion of this volume (pages 1 to 89) contains Rehn's journal entries from his "1947 Southwestern Orthoptera Survey." Journal entries date from July 16th to September 6th. Collecting began on July 25th in the region between Trinidad and Alamosa, Colorado. The area surveyed includes southern Colorado, southern Utah, northern Arizona, Southern Nevada, south-eastern California, central New Mexico, and northern Texas. The survey ended in the region of Amarillo, Texas on August 29th.

Rehn's field notes from his "1950 Iowa to Wyoming Survey" are on pages 91 to 158 of this volume. Journal entries date from July 29th to September 14th. Collecting began on August 4th in north-western Iowa, near Okoboji Lake (Dickinson County), where Rehn was hosted by the Iowa Lakeside Laboratory from the 6th to the 16th of August. The area surveyed includes northern Iowa, southern South Dakota (along what is now Interstate 90) including Badlands National Monument, Wyoming, including Yellowstone National Park, Colorado, and Nebraska. This portion of the journal contains a summary of Rehn's impressions on Orthoptera in the region surveyed between August 4th until September 2 (pages 141 to 143). The survey ended in the region of Kimball, Nebraska on September 8th.

The final survey recorded in this volume is Rehn's 1951 survey, which Rehn referred to as "Southwest - N. M. to California and Texas" (pages 160 to 257). Journal entries date from July 13th to September 21st. Collecting began on July 21st in New Mexico, east of Colfax, between Raton and Santa Fe. The survey continued through New Mexico, Arizona, Nevada, and California. The survey continued throughout Arizona, from August 25th to September 4th, and then into Texas. On September 14th Rehn worked at five stations between Abilene and Fort Worth, Texas, then began his return trip through Louisiana, Mississippi, Alabama, Tennessee, Virginia, and Pennsylvania. As Rehn had previously surveyed this region, this journal contains many references to stations visited in 1921 and 1937.

This journal also contains a variety of lists: "list of mail" (page 296); "1951 Tentative Schedule" (pages 297 to 298); "1950 Tentative Schedule" (pages 299 to 300); "1950 Mail addresses" (last page, obverse); and "1951 Mail addresses" (last page, reverse).

A group of receipts were found at the end of this volume. These items have been removed from their original location and are described separately in this collection as "Travel expense documents, circa 1961."