On top of Belknap Crater, there is a high cinder cone, which may be the surface extension of the inner pyroclastic core. Within it are three craters, all of different size, which align along a north-northwestern trend. The southern crater is large and produced most of the tephra that covers the surrounding area; the northernmost crater is smaller and erupted ash and a lava flow, which breached the rim of the crater. The Little Belknap volcano erupted lava flows that formed steptoes out of two hills by surrounding them with black, basalt. Its most recent eruptions filled its crater and created a mound of red rock with clinkers; there are a number of collapsed lava tubes diverging radially from the crater.