Petroglyphs in Ojito Wilderness
The Ojito Wilderness is a Wilderness only by modern standards. In addition to the Navajo and Hispanic ruins and artifacts found in these 11,183 acres, there are also some Ancestral Puebloan ruins. So today's rocky soils, rugged terrain and almost non-existent water supply didn't stop people (and other creatures) from living here in the past. If we look a bit further, we find the 150 million-year-old Morrison Formation exposed here is full of the fossilized remains of plants, trees and rare dinosaurs. For that matter, the skeleton of a Seismasaurus found at Ojito Wilderness is one of the largest dinosaur skeletons ever found. And mixed in with the dinosaur bones are large segments of petrified trees, indicating an ancient forest grew here beside a flowing river (because it takes a flowing river to petrify trees). So at one time or another, this area had to be quite livable. Knight's milkvetch, grama grass cactus and Townsend's aster, three rare modern plant species, are all found at Ojito. And stands of Ponderosa pines are found here now, well below the normal elevation for Ponderosas in New Mexico. Is something strange at work here? We'd have to ask the modern mobile occupants of this countryside: elk, mule deer, pronghorns, reptiles, rattlesnakes, and mountain lions...
There are miles and miles of terrain available for hiking in the deep, meandering arroyos. Along the hike you'll find millions of years of sedimentary deposits exposed in the arroyo walls and cliff faces above. If you find something really interesting, chances are it's illegal to do more than just look. Unless, of course, you are a professional paleontologist in possession of a valid permit...
Primitive camping, hiking, backpacking, sightseeing and horseback riding are allowed with no permits needed. But guides, outfitters and commercial film ventures need a Special Use Permit to operate.
To get to the Ojito Wilderness: About 20 miles northwest of Bernalillo on US 550 (about 2 miles south of San Ysidro), turn left (west) on the Cabezon Road (CR 906) and follow the left fork. There are two parking areas on the other side of the road near signs marking the wilderness. The nearest facilities of any sort are in San Ysidro, about 10 miles away.
Ojito Wilderness is open year round with no fees. Because this is a designated wilderness area, no motorized or mechanized vehicles (including mountain bikes) are allowed past the parking area. The Ojito Wilderness Study Area is located on the north side of Ojito Wilderness. It is a small bit of acreage being considered for inclusion into the wilderness area. The only way to get there is across Ojito Wilderness.
Maps: BLM - Albuquerque, Los Alamos
Ojito Wilderness with Cabezon Peak in the distance
A view in Ojito Wilderness
Ojito Wilderness area map
Other photos and map courtesy of the Bureau of Land Management
Geologic Time Scale
The K-T Boundary is that white band beneath the upper layer of sandstone
|Subdivisions based on Strata/Age||Radiometric Dates (millions of years ago)|
|Cretaceous-Tertiary Extinction Event||65|
|Permian-Triassic extinction event||251-260|
The table to the right gives a rough breakdown of the geological ages of Earth as used in modern Geology texts.
Much of the oil and gas we use comes from vegetative deposits made during the Permian and Pennsylvanian (late Carboniferous) ages. A lot of the coal we use (with its accompanying methane gas) comes from the great jungles and forests of the Mississippian and Pennsylvanian (early and late Carboniferous) ages in the Paleozoic era. Big reptiles and dinosaurs lived out their lives during the Triassic, Jurassic and Cretaceous Periods of the Mesozoic Era.
It was at the end of the Cretaceous Age that the Laramide Orogeny was set in motion, the Colorado Plateau uplifted and the Ancestral Rocky Mountains built. That was also during the time when an asteroid impacted near the Yucatan Peninsula and tipped the environmental scale in a direction that wiped virtually all the dinosaurs from the face of the planet. The K-T Boundary is a thin layer of iridium that filled the atmosphere during that explosion, then fell back to Earth during the global fires and the atmospheric upheaval afterward. While there have been plenty of marine, insect, reptile, amphibian, plant and mammal fossils found from times since, there has never been a dinosaur fossil found from the years after that impact. The K-T boundary is accepted as the definitive marker between the Cretaceous and Tertiary Ages, the marker of the Jurassic extinction event.
The Permian-Triassic extinction event seems to have happened in two major pulses about 9 million years apart. During the Permian age many insect orders had grown huge. A rise in CO2 in the atmosphere led to a rise in temperature and to acidification of the oceans. Marine invertebrates with carbon-based skeletons suffered worst but this was also the only mass extinction that affected insects: eight or nine insect orders became extinct and ten more suffered greatly reduced diversity. Insects, however, had generally recovered by the late Triassic, everything but that giant size anyway. The second pulse seems to have occurred around the time of the Araguainha impact, an asteroidal impact in Brazil that was not large enough to set off catastrophic extinction by itself but it occurred in an area filled with oil shale and the resulting sudden rise in global warming from the fires that ignited may have begun the atmospheric cascade that led to ocean surface temperatures around 104°F (40°C). That high an ocean temperature meant it was too hot for many marine species to survive. When it was over, more than 70% of terrestrial species and almost 90% of marine species had died out. Some land ecosystems took 30 million years to recover.