Geologic Map of the Maysville Quadrangle, Chaffee County, Colorado

Figure 10. View west up South Arkansas River valley overlooking west Maysville.
Showing broad alluvial flood-plain (Qal) and wedge failures Slide Blocks II (2)
and III (Qlso) in distance.
Qbo Bull Lake outwash deposits, undivided (middle Pleistocene) – Brownish-gray
to light-gray, sandy, bouldery alluvium. Mapped at the head of Walden Gulch, in lower
Cree Creek, on the west side of the lower North Fork (Maysville Cemetery), and on the
northern side of the South Arkansas River downstream of the confluence with the North
Fork. Boulders average about 10 inches in diameter, but some are larger than 4 ft and are
well rounded to subrounded, fairly well sorted, and fairly well stratified. Composed of
Tertiary igneous and Proterozoic metamorphic and igneous rocks. Some pieces of Mount
Princeton quartz monzonite are disintegrated; other rock types are only slightly
weathered. Soil at top is moderately well developed. Potential commercial source of
gravel. Thickness generally about 20 ft but may be up to 40 ft thick beneath Maysville
Cemetery surface.
Qboy Bull Lake outwash deposits, younger (late-middle Pleistocene) – Brownishgray
to light-gray, sandy, cobbly alluvium. Mapped only on the northern side of the
South Arkansas River, downstream from Maysville, where it forms a terrace about 20
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