Qtp
Till of Pinedale age (upper Pleistocene)
Xbq
Quartzofeldspathic biotite schist and gneiss (Paleoproterozoic)
Xfb
Biotite granofels (Paleoproterozoic)
Qc
Colluvium (Holocene and upper Pleistocene)
Xh
Hornblende gneiss and amphibolite (Paleoproterozoic)
Kpu
Pierre Shale, upper shale unit (Upper Cretaceous)
Qr
Rock glacier deposit (Holocene and upper Pleistocene)
NPei
N$i
Intrusive rocks, undivided (Miocene to Oligocene)
Qta
Talus deposits (Holocene and upper Pleistocene)
Pemv
$mv
Middle Park Formation, volcanic unit (Paleocene)
Pelx
$lx
Intrusive tuff-breccia (late Oligocene)
Kpl
Pierre Shale, lower shale unit (Upper Cretaceous)
Kps
Pierre Shale, middle sandy unit (Upper Cretaceous)
Qo
Organic-rich sediment (Holocene and upper Pleistocene)
w
Open water
Qva
Mountain valley alluvium (Holocene and upper Pleistocene)
Qls
Landslide deposits (Holocene and upper Pleistocene)
YXp
Pegmatite (Mesoproterozoic and (or) Paleoproterozoic)
Kmw
Middle Park Formation, Windy Gap Volcanic Member (Upper Cretaceous?)
Kd
Dakota Sandstone (Lower Cretaceous)
YgLP
Granite of Longs Peak batholith (Mesoproterozoic)
Qtp?
TRPc
^Pc
Chugwater Formation and older units (Lower Triassic and Upper Permian)
Qgy
Stream-terrace gravel deposit (Holocene and upper Pleistocene)
Kn
Niobrara Formation (Upper Cretaceous)
Peqla
$qla
Quartz latite of Apiatan Mountain (late Oligocene)
NPeg
N$g
Fluvial gravel (Miocene and upper Oligocene(?))
Perp
$rp
Rhyolite porphyry (late Oligocene)
NPet
N$t
Troublesome Formation (lower Miocene and upper Oligocene)
Qtb
Till of Bull Lake age (upper and middle Pleistocene)
Pema
$ma
Middle Park Formation, arkosic unit (Paleocene)
Peba
$ba
Basalt and trachyandesite (upper Oligocene)
Qdf
Debris flow deposit (Holocene)
Qlo
Loess (Holocene and upper Pleistocene)
Pev
$v
Volcanic rocks, undivided (upper Oligocene)
Xf
Granitic gneiss (Paleoproterozoic)
Pebi
$bi
Intrusive basalt (late Oligocene)
Jm
Morrison Formation (Upper Jurassic)