Pistapaug Mountain, or Paug Mountain, is a small traprock ridge in Durham, Connecticut, northeast of New Haven, but it holds unusual geological and ecological importance. Part of the Metacomet Ridge, it was formed from basalt lava laid down near the end of the Triassic Period and later tilted by faulting and earthquakes, creating steep cliffs, ledges, and a rugged ridgeline. Those features support diverse habitats uncommon in much of Connecticut and make the mountain a noted raptor migration route. It also serves as an important aquifer and drinking water source, offers west-facing overlooks, and is crossed by the Mattabesett Trail for low-impact recreation.