— April 14, 2021
El Cerro de Tomé comprises the remnants of a Pliocene volcano that likely was once much larger than the present-day 383-feet-high hill climbed by so many Good Friday pilgrims. Along the trails to the summit, one can view xenoliths of "country rock" (the pre-existing rock through which the volcano's lava was erupted) within the andesite that erupted approximately 3.5 million years ago. To the east of El Cerro de Tomé (left side of the photograph), ancestral Rio Grande deposits are too high above the modern river for irrigation. The lower-elevation floodplain surrounding and west of the volcano is made of much younger Rio Grande deposits and is well-irrigated, as evidenced by the verdancy in the foreground. Through the early morning haze, one can make out the Los Pinos Mountains, Turututu, the Chupadera Hills, the Magdalena Mountains, and the eastern foothills of the Sierra Ladrones.
— Kevin Hobbs, NMBGMR Field Geologist