In the eastern part of the Boring cluster, volcanic vents have average diameters less than , with average heights less than from base to summit. The lava flows from Highland Butte and Larch Mountain, both shield volcanoes, encompass a wide area, with Boring Lava deposits averaging thicknesses of not considering areas next to volcanic cones in the field. Most of the summit craters have been destroyed, though there are partial craters at Bobs Hill (located northeast of Portland) and Battleground Lake (located north of Portland); Mount Scott also has an intact summit crater. However, many of the Boring cones retain the shape of a volcanic cone, with loess extending above an elevation of . The Rocky Butte plug, which reaches a height of above its surroundings, was dated to 125,000 ± 40,000 years old by R. Evarts and B. Fleck from the United States Geological Survey (USGS). Mount Tabor is also prominent in the area, dated by the USGS to 203,000 ± 5,000 years old, as are Kelly Butte, Powell Butte, and Mount Scott. Scott has been dated to 1.6 million years ago.