Abstract <p>This article compares the earthen kurgan constructions and building technologies of seven burial mounds (kurgans) of the Bronze Age Yamnaya culture in the Orenburg oblast. We have conducted a comprehensive analysis to determine the source materials for kurgan construction and primary earthen building techniques used to create kurgans, focusing on the macro-, meso-, and micromorphological properties. This has made it possible to prove that ancient people did not simply pile up earthen materials in a chaotic manner but always used specific building plans, skills, and technologies available at that time. We have noted similarities and differences in the structure of earthen constructions based on the results of studying the kurgans of the Yamnaya culture from the beginning of the developed stage A to the end of the developed stage B (3300–2600 cal BC). Some of the identified differences are determined even by slight changes in environmental conditions and, consequently, in the available raw materials, which influenced construction materials and technologies. Analysis of all kurgans has revealed the main way of their building, namely, the creation of “pestrotsvet” (patchy-colored material) and techniques used for this purpose: kneading, tamping, and inclusion of artificially introduced material. The primary material was formed by local soils, with the addition of various inclusions (river silt, bones, coals, etc.). The kurgan size, particle-size pattern of the initial material, and its resulting cementing properties determined whether the material should be extensively kneaded and tamped or required a more complex design.</p>