Hoodoo Mountain contains at least two sets of prominent cliffs, producing a discontinuous, step-like topographic profile. The base of Hoodoo Mountain is largely delimited by a series of cliffs that range from to high, while Hoodoo's southeastern flank is relatively gentle. Here, lava flows from the most recent volcanic activity cover earlier topography; the southeastern flank is smooth from around the summit to the Iskut River. The top of the lower cliff ring defines a broad bench with an elevation of about that terminates against an upper set of cliffs. The seconed set of vertical cliffs is between and high and surrounds the summit. A prominent dike, known as The Monument, rises more than in elevation on Hoodoo's southwestern flank and is the remnants of a volcanic vent surrounded by thick deposits of lava and breccia formed during subglacial eruptions.