Cabezon – Shark Tooth Ridge – and the Rio Puerco Necks

If you have ever driven north on U.S. Highway 550 from Bernalillo, New Mexico towards Colorado, you’ve undoubtedly seen Cabezon. You can’t miss it – it’s a huge volcanic plug. But it’s only the tip of the iceberg. It is at the north end of what may be the largest concentration of volcanic necks and plugs in the world! There is nothing in the country quite like the Cabezon area, and it is truly worthy of National Park status!

Volcanic necks and plugs are where magma (lava) has solidified inside a volcano. What we see today is what’s left after the softer surrounding cone or material has eroded away

One the best places to take in this incredible scenery is from Shark Tooth Ridge about three miles south of Cabezon. To reach Shark Tooth Ridge, take U.S. 550 to County Road 279. CR 279 is not marked, but it is just north of Mile Marker 41 and is the road to the small settlement of San Luis. Follow CR 279 west and south through San Luis to where the pavement ends in about 8 ½ miles. Now is the time to start watching your odometer as you continue south. (A word of caution, unpaved roads are very dangerous to drive on when wet.)

In about 3.9 miles from the end of the pavement, CR 279 will veer to the right and continue towards Guadalupe Outlier (Hike 37 in the 3^rd edition of 60 Hikes within 60 Miles: Albuquerque). We’ll bear to the left and head towards Cabezon. We’ll pass the turn to the Cabezon trailhead (Hike 35 in the 3^rd edition of 60 Hikes within 60 Miles: Albuquerque) in another 2.9 miles.

As we pass Cabezon, Cerro Chafo will be on our right.

In about 1.2 miles south of the Cabezon trailhead access, we’ll veer to the left. Cerro de Santa Clara and Cerro de Guadalupe will also be to our right.

We’ll reach Shark Tooth Ridge in about 2.5 more miles. It’s an unmarked turn-off on the right-hand side of the road. There is plenty of room for several cars to park.

Shark Tooth Ridge gets its name because people have found shark teeth and other marine fossils in the area. I have found shark teeth in the upper Rio Puerco basin, but I have never found a shark tooth at Shark Tooth Ridge. Finding a shark tooth is a random event that depends on what the recent rains have washed out of the ground.

As you walk around Shark Tooth Ridge and look to the south, you will be staring into the heart of the Mount Taylor volcanic field.

Cerro Cochino will be immediately to your left (east) with Mesa Prieta just beyond Cochino to the southeast.

Off to your right (west), there will be many more volcanic necks backed up by the looming presence of Mesa Chivato.

Both Mesa Chivato and Mesa Prieta are capped with a thick layer of volcanic basalt and are believed to be part of the same volcanic field flowing northeast from Mount Taylor. When Mount Taylor stopped producing magma, volcanic activity continued in the northeast portion of the volcanic field in the form of vents and smaller volcanoes.

Mesa Chivato and Mesa Prieta are now separated by the Rio Puerco. And within the Rio Puerco basin there are close to fifty volcanic necks.

Since Mount Taylor is less than Five Million years old, it is considered to be a young volcano. Geologists believe that volcanic activity continued in the area up until Two Million years ago. So what you are looking at is the product of Two Million years of erosion! It’s amazing what wind and water can accomplish, if given enough time, when it encounters an uncountable number of layers of sedimentary rock, with varying degrees of hardness, overlaid with a thick coating of hard volcanic rock!

Continuing with our tour at Shark Tooth Ridge.

As we look to the south, we can see volcanic necks all the way to the horizon. The tallest neck far off to the south is Cerro de Nuestra Senora.

When we turn around, we’ll be looking back at Cabezon to the north.

Cabezon, Cerro Chafo, Cerro de Santa Clara, Cerro de Guadalupe, and Shark Tooth Ridge are all on public land managed by the Bureau of Land Management (BLM). There is some State Trust Land very close by, so it doesn’t hurt to have a State Land Office Recreation Access Pass if you’re going to do some hiking

Cerro Cochino and Mesa Prieta to the east are both on private land and off-limits to hiking. In fact, if you drive south on the road for another mile, you’ll run into signs telling you to stop and to turn around. Basically, most of the land to south is private and off-limits to hiking.

Fortunately, there is plenty of land open to exploring and no amount of private land can detract from one of the greatest scenic views in the entire country!