Who controlled Gansu during the 1920s and 1930s?

During the 1920s and 1930s, Gansu was controlled by Muslim warlords, specifically the Ma clan. While these leaders were courted by both Japanese and Russian interests, they ultimately accepted the nominal authority of the Nationalist Party in the region.1

Additionally, Communist influence began to emerge in the province during the early 1930s, expanding significantly following the Long March of the Chinese Red Army to Shaanxi. By the late 1930s, this led to the establishment of a communist-controlled Shaanxi-Gansu-Ningxia border government.1