Shu controlled the upper Han valley and the territory west of the Yangtze Gorges. The Qinling Mountains divided Shu and Wei. Wei held control over the Wei and Huai valley, where agricultural garrisons were established at Shouchun and Hefei to defend Huai. Military sorties by Wu against Hefei and Shouchun would consistently end in failure, thereby confirming Wei's hold over Huai. Wu controlled all of the Yangtze valley. The territory between the Huai and Yangtze was a desolate area, where a largely-static frontier between Wei and Wu had formed at the lower Han valley.