Traveling diary of S.L. Vladislavich-Raguzinsky as a source for identifying the location of the Ust-Tartas outpost

The article discusses the location of the Ust-Tartas outpost using the previously unused written sources, including the traveling diary of S.L. Vladislavich-Raguzinsky, the ambassador of the Russian Empire, who traveled to Beijing via Siberia in 1725. The article summarizes the archeological evidence related to the Ust-Tartas outpost. It is established that different written sources provide contradicting information on the location of the site. The analysis of the traveling diary has shown that the Ust-Tartas outpost was in fact two objects - small fortress and camp - separated by a significant distance. According to the description, the fortress was located on the right bank of the Tartas River where it flows into the Om River. There are three hypotheses concerning the location of the camp.