Results are presented from DNS of Mach 6 flow around an isolated roughness element. The conditions correspond to experiments conducted at the Purdue Mach 6 quiet wind tunnel. Solutions are obtained on fairly large grids using a high order, low dissipation scheme that is capable of resolving the very small scales in the flow. The computations explore the creation of disturbances upstream of the protuberance and follow their growth as they travel downstream. The three cases correspond to Reynolds numbers in the range 45000-55000 and transition to turbulent flow occurs in the highest Reynolds number case.