Five Years of Uŋčí Makhá Park

I've been doing some paleo events concerning hometown Mississippi National River & Recreation Area, giving me the opportunity to revisit some places. While doing this I realized A) I'd been visiting Uŋčí Makhá Park for almost exactly 5 years, and B) I'd inadvertently been doing an unplanned but reasonably effective version of repeat monitoring of specific fossils (in other words, I kept taking pictures of the same things). Previously I'd commented on how fossils had gotten along over the winter of 2022–2023. Now we can see how some have been fairing over four or five years of photographs. First, though, it's instructive to see how the overall setting has changed. Here's the south part of the "quarry" at the end of October in 2022, a few months after the park opened, photo facing south:

Here it is at the end of October, 2026:

Two things stand out (well, three: yes, I was standing at about the same point but took the photos at different angles). First, vegetation is filling in. Second, notice the outcrop wall on the left. In 2026, it's noticeably less clean. The slope here rises to the east (left), so groundwater is draining through the rocks on that side. Similarly, here's the north part of the "quarry" in 2022, again looking south:

And in 2026:

My placement wasn't as precise (since I didn't know I was doing repeat photography), but again, more vegetation and more gunk on the east wall. Now let's see some fossils. First is a bivalve steinkern, first photographed in November 2022:

A photo taken in May 2023 shows it about the same. By October 2024, though, something is definitely different:

A crack has developed, cutting through the margin of the fossil. Note also that the "shelf" just above it in the picture does not look to be as firmly attached. Now let's go to October 2026:

The setting is radically different. The "shelf" is gone (that's where the scale bar is). The block the fossil is on is crumbling; in fact, it was falling out when I got there, and I pushed it back in to take the photo. I would not be surprised if it falls out over the winter, making this the final photo I get of it. Next, let's look at a cheek spine from an Isotelus. Here it is in May 2023:

Here it is in September 2024. Pretty similar, but note the point of the spine:  

It's slightly damaged, appearing to have flaked away a bit. Now here it is in October 2026:

Fortunately, it's about the same. Finally, here are some photos of an enigmatic feature I just call a "potato chip". Here it is in May 2023:

Incidentally, I'm happy to take suggestions! It looks like the outer surface of some nautiloids, although if that's the case where's the rest of it? Is it just a fragment? Anyway, here it is in September 2024:

Like the bivalve, a large crack has developed (and please forgive the different placement of the scale bar. Like I said, this wasn't intentional monitoring). How is it in October 2026?

The crack has gotten wider, although the fossil itself is in about the same condition. We'll see if it goes as far as the bivalve in the next year or two.

All three fossils share a piece of timing: damage of some kind appeared between May of 2023 and September of 2024. The obvious suspect is the second winter of exposure, 2023–2024, although unfortunately my photographic interval isn't fine enough to say for sure. (I have dozens of photos from April 2023, but for some reason did not photograph these fossils.) It's interesting that additional changes have not been as notable; further damage has primarily been "improvements" on the 2023–2024 damage.

I'm rather pleased with this exercise. I don't often think of MNRRA in terms of paleontological monitoring; things come and go so quickly here from the Decorah, and, well, sometimes you don't think of the things at home the same way you think of things at places you have to travel to get to. Completely out of nowhere, whoever it was who decided to daylight Hidden Falls Creek this way has laid a beautiful monitoring case right in my lap, and it only took me five years of puttering around to realize it.

If you've gotten through all this and are weary of Platteville invertebrates, the fall 2026 issue of Park Paleontology News is up. Go check it out!