CLICK ON A COLORED AREA OF THE GEOLOGY MAP TO SHOW INFORMATION HERE
	wtr	---	water	---
	ice	Holocene	ice	---
	Qf	Holocene	artificial fill, including modified land	---
	Qiad(2)	Holocene	intrusive andesite and dacite	Mount St. Helens, rocks and deposits of
	Qiad(3)	Holocene	intrusive andesite and dacite	Mount St. Helens, rocks and deposits of
	Qva(1sh)	Holocene	andesite flows	Mount St. Helens, rocks and deposits of
	Qva(2sh)	Holocene	andesite flows	Mount St. Helens, rocks and deposits of
	Qvb(2sh)	Holocene	basalt flows	Mount St. Helens, rocks and deposits of
	Qvc(1sh)	Holocene	volcaniclastic deposits or rocks	Mount St. Helens, rocks and deposits of
	Qvc(2sh)	Holocene	volcaniclastic deposits or rocks	Mount St. Helens, rocks and deposits of
	Qvc(3sh)	Holocene	volcaniclastic deposits or rocks	Mount St. Helens, rocks and deposits of
	Qvl(3sh)	Holocene	lahars	Mount St. Helens, rocks and deposits of
	Qvp(3sh)	Holocene	pyroclastic flows	Mount St. Helens, rocks and deposits of
	Qa	Quaternary	alluvium	---
	Qls	Quaternary	mass-wasting deposits, mostly landslides	---
	Qv(sh)	Quaternary	volcanic rocks	Mount St. Helens, rocks and deposits of
	Qvb(tl)	Quaternary	basalt flows	Thomas Lake, basalt of
	Qvc(sh)	Quaternary	volcaniclastic deposits or rocks	Mount St. Helens, rocks and deposits of
	Qad(e)	Pleistocene	alpine glacial drift, Fraser-age	Evans Creek Drift
	Qad(e)	Pleistocene	alpine glacial drift, Fraser-age	Evans Creek Drift
	Qao	Pleistocene	alpine glacial outwash, Fraser-age	---
	Qao(e)	Pleistocene	alpine glacial outwash, Fraser-age	Evans Creek Drift, outwash deposits of
	Qap(lh)	Pleistocene	alpine glacial drift, pre-Fraser	Logan Hill Formation
	Qapo(e)	Pleistocene	alpine glacial outwash, pre-Fraser	Evans Creek Drift, outwash deposits of
	Qapo(h)	Pleistocene	alpine glacial outwash, pre-Fraser	Hayden Creek Drift, outwash deposits of
	Qapo(wh)	Pleistocene	alpine glacial outwash, pre-Fraser	Wingate Hill Drift, outwash deposits of
	Qapt(h)	Pleistocene	alpine glacial till, pre-Fraser	Hayden Creek Drift, till deposits of
	Qapt(h)	Pleistocene	alpine glacial till, pre-Fraser	Hayden Creek Drift, till deposits of
	Qat(e)	Pleistocene	alpine glacial till, Fraser-age	Evans Creek Drift, till deposits
	Qgu	Pleistocene	glacial drift, undivided	---
	Qiad(1)	Pleistocene	intrusive andesite and dacite	Mount St. Helens, rocks and deposits of
	Qt	Pleistocene	terraced deposits	---
	Qva(mm)	Pleistocene	andesite flows	Marble Mountain, andesite flows of
	Qva(tp)	Pleistocene	andesite flows	Timbered Peak, andesite flows of
	Qvb	Pleistocene	basalt flows	---
	Qvb(mm)	Pleistocene	basalt flows	Marble Mountain, basalt flows of
	QPLiad(g)	Pleistocene-Pliocene	intrusive andesite and dacite	Goat Mountain, dacite porphyry of
	PLMc(t)	Pliocene-Miocene	continental sedimentary deposits, conglomerate	Troutdale Formation
	Mva	Miocene, upper	andesite flows	---
	Mc(w)	Miocene, mid-upper	continental sedimentary deposits, conglomerate	Wilkes Formation
	Mipb(sl)	Miocene, mid-upper	pebble breccia	Spirit Lake pluton
	Mid	Miocene	diorite	---
	Mv(g)	Miocene, middle	basalt flows	Grande Ronde Basalt, Columbia River Basalt Group
	Mial(s)	Miocene, lower	argillic alteration	Spirit Lake pluton
	Migd(sl)	Miocene, lower	granodiorite	Spirit Lake pluton
	Miq(sl)	Miocene, lower	quartz diorite	Spirit Lake pluton
	Miqm(s)	Miocene, lower	quartz monzonite	Spirit Lake pluton
	Mva(cb)	Miocene, lower	andesite flows	Council Bluff, volcanic rocks of
	Mva(s)	Miocene, lower	andesite flows	Smith Creek Butte, andesite of
	MOian	Miocene-Oligocene	intrusive andesite	---
	MOva(2)	Miocene-Oligocene	andesite flows	---
	MOva(3)	Miocene-Oligocene	andesite flows	---
	MOvb(2)	Miocene-Oligocene	basalt flows	---
	MOvb(3)	Miocene-Oligocene	basalt flows	---
	MOvc(2)	Miocene-Oligocene	volcaniclastic deposits or rocks	---
	MOvc(3)	Miocene-Oligocene	volcaniclastic deposits or rocks	---
	MOvd(3)	Miocene-Oligocene	dacite flows	---
	MOvt(3)	Miocene-Oligocene	tuffs and tuff breccias	---
	Ova(1)	Oligocene, lower	andesite flows	---
	Ovb(1)	Oligocene, lower	basalt flows	---
	Ovc(1)	Oligocene, lower	volcaniclastic deposits or rocks	---
	Ovd(1)	Oligocene, lower	dacite flows	---
	Ovt(1)	Oligocene, lower	tuffs and tuff breccias	---
	OEm(lc)	Oligocene-Eocene	marine sedimentary rocks	Lincoln Creek Formation
	OEn(t)	Oligocene-Eocene	nearshore sedimentary rocks	Toutle Formation
	OEva	Oligocene-Eocene	andesite flows	---
	OEva(g)	Oligocene-Eocene	andesite flows	Goble Volcanics
	OEvc	Oligocene-Eocene	volcaniclastic deposits or rocks	---
	OEvc(g)	Oligocene-Eocene	volcaniclastic deposits or rocks	Goble Volcanics
	En(c)	Eocene, mid-upper	nearshore sedimentary rocks	Cowlitz Formation
	Evb(gr)	Eocene, mid-upper	basalt flows	Grays River, volcanic rocks of
	Eva	Eocene	andesite flows	---
	Evd	Eocene	dacite flows	---
	Evt	Eocene	tuffs and tuff breccias	---