The landscape of the NW Iranian Plateau in the Arabia- Eurasia continental collision system results from the interplay between climate and tectonics. The Talesh Mts. along the margin of the plateau exhibit characteristics of a transient landscape shaped by the spatial variability of precipitation, bedrock erodibility, and active tectonics. The influence of the orographic rainfall and its erosional efficiency on topographic building processes, however, is still unknown. To explore the interplay between these factors, we present 11 new erosion rates derived from meteoric 10 Be on the eastern (wetter) and western (drier) flanks of Talesh Mts. We also examine their relationship with ksn and ksnQ metrics considering the spatial rainfall variations. The erosion rates range from ⁓100 to 400 m/Myr, with lower values in the interior, and higher values in the plateau exterior with a positive correlation with topographic metrics. Mountain building and erosion in the range likely started around 12 to 10 million years ago, as suggested by rock uplift histories inferred from river profile inversion analysis. This caused a progressive concentration of precipitation along the windward orogenic side, enhancing tectonic activity. The stationary nature of the range over the last few million years may result from more efficient sediment removal on the wet flank. This feedback could have been amplified during the base-level drop of the Caspian Sea.