The Hinggan Mountains are divided into inner and outer ranges： those north of the Heilongjiang River are the Outer Ranges， while those to the south are the Inner Ranges. The mountains west of the Nenjiang River are known as the Da Hinggan Range. Mount Soyolji 索岳尔济山， serving as the primary ridge of the Da Hinggan Range， is characterized by dense forests and abundant wildlife； Emperor Kangxi 康熙帝 praised it as a renowned scenic spot for its majestic landmark. Following imperial orders， the jiangjun of Heilongjiang designated Mount Soyolji as a royal hunting ground， which made it an important place for the Qing emperors to build close relations with various tribes. However， a major forest fire during the reign of Emperor Qianlong 乾隆帝 led to its closure. The royal hunting ground existed for nearly a hundred years. During this time， Emperor Kangxi visited it twice， while Emperor Qianlong had plans but never went. The National Archives of Mongolia holds a map of the Soyolji hunting ground， which serves as a critical source for delineating tribal nomadic territories for its detailed markings of various karuns and minor paddocks across the Hinggan Mountains. As this area was designated a royal hunting ground， the natural resources of the Hinggan Mountains received effective protection， and after its closure， the tribes’ geographical spread was no longer restricted. In the Qing dynasty， the royal hunting grounds were not only places for hunting and martial exercises but also political stages for winning people’s loyalty.