<p>Damming-induced river dis-connectivity represents one of the most pervasive anthropogenic perturbations to global river systems. We report detrital apatite fission-track (AFT) thermochronology from modern sediments of the upper Yellow River and the Wei River, and compare these data with bedrock AFT signatures from the adjacent northeastern Tibetan Plateau as a potential primary sediment source. The results reveal pronounced spatial variability in age‑component proportions along the uppermost Yellow River but only minor downstream change along the Wei River. These patterns can be reasonably explained by extensive cascade damming and reservoir trapping in the uppermost Yellow River versus minimal impoundment in the Wei River. Impoundments have reduced sediment connectivity, disrupted sediment loads, and likely altered hydrological dynamics and associated ecosystems. The provenance trends of the upper Yellow River from the Guide region to the West Ordos Block segment documented here challenge interpretations that attribute sediment supply throughout the upper Yellow River solely to large-scale exhumation of the Tibetan Plateau; instead, they indicate substantial contributions from localized sources, including adjacent mountain ranges and Cenozoic basins. Collectively, our interpretations demonstrate that anthropogenic infrastructure has produced partially blocked sediment routing along discrete river reaches and, at the scale of local river systems, can dominate over natural tributary-driven sediment mixing. These findings underscore the urgent need to evaluate the socio‑economic and eco‑environmental consequences of disrupted sediment connectivity and to integrate connectivity preservation into sustainable river management and mitigation strategies.</p>