The southern boundary of the fell is formed by the Whinlatter Pass road. The summit of the pass lies south east of Whinlatter Top, marking the line of the Derwent-Cocker watershed. This falls from Tarbarrel Moss to the road, bypassing the highest point of the fell so that all of its waters flow to the Cocker. From the road summit Whinlatter Beck runs westward beneath the steepest face of the fell, Whinlatter Crag being a little below the highest point. To the north of Whinlatter is the quiet valley of Aiken Beck, its entrance neatly hidden in the woods between Brown How and Graystones. Its tributaries Willybrag Gill and Drycloff Gill drain the slopes of the fell. One wonders at the derivation of the former name. Aiken Beck and Whinlatter Gill combine to form Blaze Beck, a sizeable stream flowing into the Cocker at Low Lorton.