It is exposed in a small belt along the east flank of Espinaso Ridge in the Hagan basin of central New Mexico, where it is truncated to the northwest by the San Francisco Fault and disappears to the southeast in the subsurface.

[1] The upper age range is poorly controlled but may extend into the Miocene.

[1] It is interpreted as sediments deposited in a closed basin during early rifting along the Rio Grande rift, and is the oldest exposed Santa Fe Group formation near the Albuquerque Basin.

[1] The beds were first studied in detail by Charles E. Stearns in 1953, who tentatively assigned them to the Abiquiu Formation.

[2] However, no clasts of Amalia Tuff, pervasive in the Abiquiu Formation further north, are present.