We present a three‐dimensional electrical resistivity model of the crust and upper mantle beneath the easternmost Kunlun fault (EKLf), obtained by three‐dimensional inversion of magnetotelluric (MT) data. The crust of the Songpan‐Ganzi block is characterized by high resistivity from the surface to a depth of around 20 km, and by low resistivity in the mid‐lower crust in the depth range 20–40 km. The eastern edge of the high conductivity layer is coincident with the EKLf and the Huya fault. The electrical resistivity structure provides new insights into both (1) the generation of recent M > 6 earthquakes and (2) strain partitioning on this segment of the EKLf. Our model reveals that the Huya fault is the main branch of the EKLf in the region. Together with the EKLf, the Huya fault defines the boundary between the Songpan‐Ganzi and Bikou blocks. The mid‐lower crust of the Songpan‐Ganzi block in this region has a low resistivity that likely represents a mechanically weak layer. The 2017 Jiuzhaigou Ms7.0 earthquake and other recent M > 6 earthquakes may have been controlled by the change in viscosity in the mid‐lower crust that occurs across this boundary. The high conductivity may be acting as either (1) a channel of lower crustal flow, or (2) as a weak layer that decouples the upper and lower crust. The fact that the high conductivity layer does not extend along the north side of the Sichuan Basin questions the idea that crustal flow occurs in this area.

Based on broadband magnetotelluric data collected in western Yunnan, we obtain a three‐dimensional crustal resistivity model, which reveals seismogenic structures of Yingjiang and Longling earthquakes. Our model suggests a bifurcation of the crustal flow in western Yunnan, with a southwestern branch running into the Tengchong Block north of the Dayingjiang Fault and a southeastern branch flowing into the Baoshan Block. The Yingjiang region features an upper and midcrustal resistive body above 20‐km depth, surrounded by conductors in the midcrust. Six moderate earthquakes in Yingjiang occurred in the transition zone between the resistive and conductive structures. These earthquakes occurred in the context of a right‐lateral accommodation zone between the Nabang and Binglangjiang Faults and in the presence of the southwestern branch of the crustal flow, which provides a mechanical decoupling under the rigid high‐resistive upper crust. Beneath the Longling area, a high‐resistive structure extends through the entire crust, but a zone of low resistivity is embedded in the depth range of 10–25 km where the 1976 M7.3 earthquake occurred. The high‐resistive body provides a blockage to the previously proposed crustal channel flow along the Gaoligong shear zone and may accumulate sufficient stress. The Longling strong earthquakes may result from the sinistral strike‐slip motion of the Ruili‐Luxi Fault in the framework of the north to northeast trending compressive stress. The blockage to the crustal channel flow along the Gaoligong shear zone by the high‐resistivity zone in Longling could be an important factor to produce the north to northeast trending compressive stress field in Longling area.