Mesozoic Era

Jurassic Period (187 to 208 million years ago)
Navajo Sandstone: A pale yellow layer of heavily varnished cliffs and rounded domes that was formed by Sahara Desert-like sand dunes. Visible at the Island in the Sky (Whale Rock) and in the Maze (Cleopatra's Chair).

Kayenta Formation: A dark red and brown layer of ledge forming shale's and sandstone's formed in a wet climate of crisscrossing streams. Thin layer visible above the Wingate cliffs at the Island in the Sky and the Maze.

Wingate Formation: A dark red layer of sheer cliffs and towering spires that are often heavily varnished. Formed by the compression of Sahara Desert-like sand dunes. Visible throughout the park; spires include Candlestick Tower at the Island and the Sixshooter Peaks outside the Needles.

Triassic Period (208 to 245 million years ago)
Chinle Formation: A multicolored layer (including red, brown, blue, and green) forming slopes of loose rock and dense soil below the base of the Wingate layer. Deposited by streams and erosional channels.

Moenkopi Formation: A multicolored layer (including red, brown, yellow, white and purple) forming steep slopes of broken rock with many ledges. Deposited by coastal mud flats.

Paleozoic Era

Permian Period (245 to 286 million years ago)
White Rim Sandstone: A thick, white layer of sandstone forming cliffs and the caprock of towers like the Chocolate Drops in the Maze; usually heavily varnished. Deposited by beaches and offshore sand bars during periods of flooding. The White Rim Road at the Island in the Sky contours along the White Rim bench.

Organ Rock Shale: A dark red layer of soft stone that forms towers (Land of Standing Rocks, Monument Basin) when protected by a caprock of White Rim Sandstone. Deposited by marine lowlands with streams, flood-plains and tidal flats.

Cedar Mesa Sandstone: A layer of sandstone striped red and white by interfingering with the Cutler Group. Forms spires and domes typical in the Needles and in the canyons of the Maze. Deposited by beaches and coastal dunes.

Lower Cutler Beds: A gray and red layer of ledgy cliffs found along the Green and Colorado rivers at their Confluence. Deposited by a combination of shallow seas and coastal plains.

Pennsylvanian Period (286 to 320 million years ago)
Honaker Trail Formation: A gray layer of ledgy cliffs found along the Colorado River in Cataract Canyon. Deposited by shallow seas.

Paradox Formation: A black, white and gray layer of salts visible in portions of Cataract Canyon. Deposited by the evaporation of landlocked seas.