The Redwall Limestone is an erosion-resistant, Mississippian age, cliff-forming geological formation that forms prominent, red-stained cliffs in the Grand Canyon.

As a result of studies in Yavapai County, Arizona, Gutschick[6] recognized four informal members within the Redwall Limestone and McKee[7] later formally named them.

[1][2] In ascending order, the Redwall Limestone is divided into the Whitmore Wash, Thunder Springs, Mooney Falls, and Horseshoe Mesa members.

This is indicative of a period of emergence, minor tectonic activity, and erosion between the deposition of the Thunder Springs and Mooney Falls members.

In its upper part near its contact with the overlying Horseshoe Mesa Member, one or two zones containing thin beds or lenses of chert occur.

This member is normally composed of thin-bedded, light gray, fine-grained, limestone, typically a mudstone to wackestone that commonly contains encrusting and sediment-binding algal structures.

The Horseshoe Mesa Member typically forms weak receding ledges in contrast to the massive cliff that characterizes the Mooney Falls below.

The lower contact of the Redwall Limestone is a disconformity that rests either on upon the Devonian Temple Butte Formation or, where it is missing in the eastern Grand Canyon, strata of Cambrian Tonto Group.

Normally, this basal conglomerate is composed of gravel that is locally derived from either the underlying Temple Butte Formation or Muav Limestone.

In the eastern Grand Canyon, the Temple Butte Formation consists of a thin, discontinuous layer of Devonian strata that fills paleovalleys cut into the underlying Cambrian Muav Limestone.

The duration of geologic time represented by this unconformity increases eastward across the Grand Canyon and the rest of northern Arizona.

[1][2] The upper contact of the Redwall Limestone is a disconformity that represents a buried, irregular and karstified paleosurface that contains many contemporaeous caves and collapse structures.

Filling these buried paleovalleys, paleochannels, caves, and collapse structures are sedimentary strata of the Surprise Canyon Formation.

Overlying the Surprise Canyon Formation and adjacent protruding paleosurface of the Redwall Limestone are marine, fluvial, and aeolian deposits of the Supai Group.

Subsequently, the shallow marine sediments comprising the Thunder Springs Member accumulated as the sea regressed back towards the west leaving northern as dry land.

Terrestrial weathering, erosion, and lack of sediment accumulation formed an unconfortmity separating the Thunder Springs and Mooney Falls members.

The Horseshoe Mesa Member accumulated during early Late Mississippian time as the shoreline retreated westward and back into Nevada.

Four of the five formations in the Monte Cristo share nearly identical lithologic characteristics and stratigraphic position with the four members of the Redwall Limestone in northern Arizona.