North Korea is carrying out large-scale sand and gravel extraction along its major rivers, including the Yalu, Daedong, and Chongchon, in 2026. Satellite imagery analysis reveals crews deploying large dredgers and heavy equipment, reshaping river terrain and ecosystems. Along the Yalu River, a 4.3-hectare uninhabited island north of Wihwa Island was fragmented into sandbars over six years. On the Daedong River, more than 10 extraction vessels worked on Dudan Island, a 4.0-hectare island that vanished entirely beneath the water surface after about 14 years. The Chongchon River shows extensive furrow-pattern construction traces and emerald-colored artificial ponds, indicating long-term, systematic extraction.