At the Hogsback approach up Mt. Hood near Timberline Lodge, Oregon.  From here the common way up is to take the snow ridge up to the Pearly Gates to reach the top of Hood.  This area is part of an old crater w/ active fumarole sulfur vents (note the emitting steam) known as the Hot Rocks area.  An area not to linger around long as the gases emitted lack oxygen & are poisonous, though the entire area smells like Yellowstone.  Being later in the season, a noticeable crevasse/bergschrund obstructs part of the approach to the Pearly Gates, hence making other approaches such as the nearby Old Chute route more favorable.