Carbonaceous aerosols strongly influence atmospheric radiative forcing over the Himalayas, yet their spatial variability and transport mechanisms remain poorly constrained. Here we present high-time-resolution measurements of black carbon (BC), primary brown carbon (BrC_pri), and secondary brown carbon (BrC_sec) at three high-altitude sites across the western (Purang), central (Yadong), and eastern (Zayü) Himalayas during the pre-monsoon period. Distinct spatial gradients in light absorption and biomass burning (BB) tracers (levoglucosan and K⁺) reveal pronounced regional heterogeneity. Yadong exhibits the strongest absorption (B_abs: 53.1 ± 18.5 Mm^−1 at 370 nm; 14.2 ± 5.5 Mm^−1 at 880 nm) and the highest BB influence, indicating a central Himalayan hotspot of polluted aerosol accumulation. BC dominates light absorption across all sites, with its contribution increasing eastward and reaching ~95 % at 660 nm in Zayü. In contrast, BrC contributions exhibit strong regional contrasts, with BrC_pri dominating absorption in Yadong (8–28 %) and BrC_sec enhanced in Purang (3–26 %). Trajectory analyses indicate that central Himalayan aerosol loading is strongly modulated by orographic uplift and terrain-driven circulation. CALIPSO observations further demonstrate a transition from mineral dust in the west, to pollution-modified dust in the central Himalayas, and biomass-burning aerosols in the east. These results improve our understanding of the sources, transport pathways, and atmospheric transformations of BC, BrC_pri, and BrC_sec in the Himalayas.