Night Sky at Chaco Culture National Historical Park, New Mexico

To protect the irreplaceable remnants of the ancient residents of Chaco Canyon (strucutures, artifacts, petroglyphs, pictoglyphs, etc.), night time access to most of the park is prohibited. In the summer, access on the loop road and backcountry trails is limited to 7am - 9pm (except for the early access on the summer solstice, for example). Besides the campground and the visitor center, the only other place you're officially able to be after 9pm is Fajada Butte Viewpoint. So I spent parts of my two overnights shooting the Milky Way from there.

The first two shots were taken before dawn, probably between 3:30 and 4:15, on the morning of June 22, 2025. I needed to wait until early morning because moonrise for the waning crescent moon was going to be around 3:30am, and I wanted the moonlight to illuminate the foreground for my shots. The first shot (probably taken later) got photobombed by what was probably an International Space Station flyby.

All shots are single exposures, high iso. Top shot was a Nikon 20mm f/1.8, ISO 2000, 25 seconds. Second shot was Nikon 35mm f/1.8, ISO 4000, 20 seconds. Third shot was a Rokinon 14mm f/2.8, ISO 6400, 30 seconds. My main night sky camera is a Nikon D780. For most untracked shots, exposures of 30 seconds or less limits the star trailing due to the earth's rotation, especially for wide-angle lenses. Processed in Lightroom for Mobile.

The first two are looking more or less west, as you can tell if you check when the Milky Way was vertical in mid-June. I assume that's Gallup and other small towns causing the orangish glow. Sunrise would have been coming from the other direction. Third one was probably southeast-ish, to capture the rising core of the Milky Way, and still fit Fajada Butte. This was probably around 11pm on the night of June 20th.

There's an actual, modern observatory at Chaco, behind the visitor center. I assumed they'd have programs every weekend, but, checking the calendar on their website, I saw no night sky programs scheduled, other than a star party, with volunteers from Albuquerque providing telescopes, the month before.

The weekend we were there would have been a good dark sky weekend for observing, but it was also the summer solstice, with numerous sun-related events going on, so I guess it's not totally surprising they didn't do any night sky stuff that weekend, but, other than the one star party, I haven't noticed any night sky events on the calendar this year (not that I check every day!). That also sort of makes sense, if only because the place is so isolated that you're not going to get a lot of "drive in for the night, then head home" drop ins, espcially not from tourists. Still, to have a spiffy observatory and not put it to use from such a dark sky location seems like a shame.

The ancient residents of Chaco certainly watched the sky, as well, as evidenced by the "supernova pictoglyph," which I noted in the previous post. What I forgot to note is, if you look on the wall below the overhang and process your shot differently, you see a large round object, with a possible tail, stretching off to the left. There's some speculation this might be a comet.

In any event, as illustrated by the shots, there's a pretty amazing night sky to be seen from Chaco Culture National Historic Park, so lots to see after dark, too. And there are occasional star parties, "manned" by volunteers from the New Mexico amateur astronomer community. I may try to volunteer for one of those some day, too.

Petroglyphs and Pictoglyphs in Chaco Culture National Historical Park, New Mexico

Post two of three for Chaco Culture National Historical Park, which I visited on June 20-22, 2025. My first post is here.

Not surprisingly, in addition to the many Ancestral Puebloan structures, there are a large number of petroglyphs and pictoglyphs in the park. Also not surprisingly, because some of these would be about 1,000 years old, many of the petroglyphs (pecked) and pictoglyphs (painted) are hard to see.

The one at the top is the one I especially wanted to see. It is widely believed that the painting is of the precursor to the Crab Nebula, which is to say, a star that went supernova, back in 1054. So, yes, nearly 1,000 years old!

It's painted on the bottom of an overhang, and gets little or no direct sunlight, helping it survive all these years. You look straight up to see it.

I've been seeing pictures of it in astronomy books and magazines for as long as I can remember. Nice to finally see it in person.

People who study archeoastronomy (ancient astronomy) determined that the crescent moon and star-like figure are roughly of the proper orientation and separation to reflect what might have been seen by an ancient skywatcher, back on July 4, 1054, when that super-bright but temporary star would have appeared in the constellation Taurus, near a crescent moon, in the early AM hours of that date.

To get to the "Supernova pictoglyph," it's about a 7 1/2 mile roundtrip walk, along a mostly-level canyon bottom. However, erosion has cut down enough to require a couple of detours. Make sure you know where you're trying to get to, so you don't get off track after the detours.

The trail to the pictoglyph is the trail that heads to Penasco Blanco. It's about another 3/4 mile past the pictoglyphs. I did not continue to them, as I was a bit rushed. If I had more time, I would have. They sound interesting.

The trail starts from near Pueblo del Arroyo, and heads mostly west, along an old dirt road. After a half mile, you pass Kin Kletso. Three-quarters of a mile past that, is Casa Chiquita. About a half mile after that, is the signed "Petroglyph trail", which parallels the main trail, but runs along the cliff.

Interestingly, there were bike racks at Kin Kletso and Casa Chiquita. Apparently, the path here is still designated as Navajo Service Road 14, so Navajo can drive that segment, and bikes are permitted. Not sure how far you can ride your bike, but, if an 8 mile roundtrip hike to Penasco Blanco sounds too far, you might want to investigate with the NPS to see how far you can ride a bike, if you have a bike. At the very least, it's about half the distance.

Other petroglyph concentrations are above Una Vida (some pictured, above), between Pueblo Blanco and Hungo Pavi, and small panels near the campground and near the administrative buildings (all of which I also visited). There are several other areas with petroglyphs and ruins that I did not visit, which I would try to visit, were I to return. Even though Chaco Culture National Historical Park looks small on a map, it's still a lot to take in, even over two days. I could defintely use two more days, just to visit the other publicized trails and areas. Unfortunately, it's a long drive from the LA area, and most airport car rentals do not allow for off-pavement driving of their rental cars, so I'm not sure when that will be. I'd probably try for an equinox trip, for the sunrise and sunset alignments, as a counterpoint to the summer solstice trip we did, this time.

Chaco Culture National Historical Park, NM

Chaco Culture National Historical Park is located in New Mexico, some three hours from Albuquerque. The closest cities are Gallup, to the south, and Farmington, to the north. From either direction, it's nearly 1 1/2 to nearly 2 hours from those larger cities to Chaco, and involves 13 miles of driving on rough dirt roads from the north, or 20 miles of the same from the south. It's slightly less than that from either side to the closest gas stations. The NPS warns that either approach can become impassable when wet.

Despite the significantly longer dirt segment, if you're coming from the south or west (Las Vegas area, Flagstaff area, or points further south and west) the overall longer drive to get to the north approach means the southern route is going to be a lot quicker. So that's what we did: I-40 east, Exit 53, for Thoreau, and NM-371. (That sign, btw, is what you see when you leave the park and head back towards I-40).

I have to say I expected the signage for Chaco off of I-40 to be more prominent (as in, a big, giant, NPS-brown sign, as opposed to a smallish green sign, nearly at the actual offramp). However, my Waze did direct correctly. Still, I did stop shortly after getting off the freeway, to confirm on a map that I was heading the right way.

The NPS site suggests not trusting gps directions, but I suspect that's from earlier iterations, and the big companies have since figured out based on user feedback how to actually get there without driving their customers into empty desert.

From NM-371, it's about 27.5 miles north, to NM-57/Navajo Service Route 9, then another 13 miles or so, to Navajo Service Route 14, which is also NM-57. That's where the pavement ends. About twenty miles later, somewhat after passing the stone NPS sign for Chaco Culture National Historical Park (which nicely frames Fajada Butte), you're back on pavement.

The drive on dirt was long, slow, but, overall, not as bad as feared. I still probably averaged less than 20mph, but the washboarding was only intermittent. I did take care approaching cattle grates, as I had read that occasionally there are big dropoffs in the transitions. Also, there were a few hills with exposed rocks and limited visibility where I slowed and drove especially carefully. But, overall, no regrets about driving a Camry from the south.

Very little traffic either way on the dirt segment. I think I saw fewer than a half-dozen cars, each way. No real sandy areas on the drive, but there were a few areas of dried mud that would have been impassible when they were still mud. In my trunk, I had a few tire mats and a shovel, but they weren't needed.

I should note that my driving experience is specific to June 20, 2025, when we drove in, and June 22, 2025, when we drove out. Based on the dried, but not yet broken down mud ruts on the road, it seems likely that driving might have been problematic a few weeks earlier. Also, a few weeks after our trip, from July 3 through July 8, 2025, Chaco's NPS webpage noted that travel to Chaco via NM-57 (the south) "was not recommended at this time." So, obviously, in driving to Chaco, figuratively, at least, ymmv. It is sugggested that you call Chaco's visitor center prior to your visit, to confirm road conditions.

After stopping at the visitor center ($25/vehicle entrance fee, or a federal recreation pass, which I had), we headed first to see the "star" of Chaco Canyon, Pueblo Bonito. BTW, the names of the structures in Chaco are mostly either descriptive Spanish or corrupted Navajo. In this case, Pueblo Bonito means something like pretty town. It's the largest of the structures remaining. Once up to four stories high and with some 700 rooms, it provides a good idea of the sprawl of these "great houses." In this case, the city is laid out along the cardinal directions, so equinox sunrise and sunset is along the long, straight, southern wall of Pueblo Bonito.

A view of Pueblo Bonito from above (from the north mesa) is a few shots below, while the previous shots were of and within Pueblo Bonito. I think the shot adjacent to this text was Chetro Ketl (slughtly east of Pueblo Bonito), while the next two are from Pueblo del Arroyo. Those are just three of the six or so named houses and "great houses" (pueblos) near or adjacent to the paved road. Roughly five other named sites are accessible via "backcountry" trails from Chaco, with lengths of 3 to 8 miles roundtrip each. Several outlying sites are even further from the pavement than that.

Some of the excavated ruins have had more modern "stabilization" work done, including the roof drain and drop pipe here, and the support sturcture a few shots up. The NPS interpreters said that, under current-day policy, these structures would likely have been left buried or reburied for stabilization, but the add-ons were done quite some time ago, and you'll note them as you walk the ruins quite easily.

As previously noted, there are about a half-dozen major ruins adjacent to or within 1/2 mile of the pavement. Just seeing those would make a pretty full day, because walking to, through, and around each site means about 3/4 of a mile, each, so it would be 3-4 miles of walking, plus 18 miles or so of driving. Spend some time in the visitor center or just standing still for a while, and there's your day, even before adding even one of the "backcountry" trails. So, while we initially had booked one night of camping, we later added a second. I was very glad we did.

The next morning was the summer solstice, which coincided with our trip, so we figured we might as well do the solstice experience. That meant lining up a little after 5am for early entrance to Casa Rinconada (normally, the gates open at 7am, and close after dark, vatying some during the course of the year). Access to this event (summer solstice sunrise at Casa Rinconada) was limited to the first 100 people. I think, as it happened, there were fewer than that lined up, so everyone who wanted to got to experience the solstice sunrise there.

Casa Rinconada is smaller than a "great" house, but has a very large excavated kiva. Originally, the kiva would have been covered, but windows and doors were present. It's possible (though not certain) that, shortly after sunrise on the summer solstice, sunlight would have shone through a window and entered a door on the opposite side. Not quite Indiana Jones, but a possible non-chance alignment.

At any rate, we made the line, convoyed in, then parked, where instructed. We were in time for the sunrise, then, later, got to watch a ray of sun shine through a window, on to the opposite wall, then eventually make its way down to another door. Again, it's possible this was by design, and something the ancient inhabitants of Chaco would have experienced, over a thousand years ago.

It's also possible that, when the kiva was reconstructed by early antropologists, they placed the windows differently, and the alignment is just a crazy accident.

Regardless of this particular alognment, there seems little doubt that many of the Chaco structures (and, indeed, the interaction of many different Chaco structures) were built with attention to the heavens. Alignments for equinox and solstice, and, more obscurely, for major and minor lunar standstills, are found all around Chaco, especially in the layout of the pueblos and casas.

Beyond the big structures, one of the more interesting previous structures involved a "sun dagger," an alignment or rocks and a spiral petroglyph atop Fajada Butte. But visitation caused those rocks to shift, and access to the top of Fajada Butte is no longer allowed, and the sun dagger no longer hits its marks for solstices and equinoxes.

I'll probably have a follow up post or two. But I'll wrap this post up with this: Chaco Culture National Historical Park is way out there. There is no food or drink available for sale, no cabins or motel rooms for rent, and no showers. The camp sites are "primitive," meaning no electrical or sewer hookups. You'll only have what you bring (except for there is running water and flush toilets), and you'll either stay in a tent or an RV you brought yourself. On the other hand, there's a small ruin, right behind campsite #26.

If you plan to stay, make reservations ahead of time via recreation.gov. Campsite availability opens three months out. It's $20/night. Other than peak weekends (solstice or equinox, I expect) it seems like you can often catch even weekend availability within a week or two of the actual date. Still, if your plans are solid, good idea to reserve early, and eat the $20 camping fee if your plans change, rather than risk not being able to go, at all. That said, if you know you're not going to make it, go back on recreation.gov and cancel, so someone else can take the spot.