Some of the rocks and petrified wood in my inventory.

Outside in the natural environment, you will often see rocks on the ground or sticking through the surface. Rocks and the things found inside them, such as fossils, are important to the world and to scientific communities because they contain a record of the Earth’s history and the life that populated it. Through rocks and fossils, we can read how the Earth and its environment changed, how the continents moved, and how life has developed over time. We can even examine natural disasters. For this reason, many museums house rocks to safeguard them and the information they hold. One of the most important parts of preserving that information is the process of a detailed inventory.

Rocks and fossils form in a variety of ways, as demonstrated by these specimens of concretions, petrified wood, and other fossils.

To perform a detailed inventory, I first removed the rocks from the collection so they could be examined more carefully and described in greater detail. I then opened their database records and went through each field to update and correct any information that was missing or incorrect. Next, I examined the rocks and fossils to ensure there was nothing severely wrong with them; a few were shedding dirt or splinters since these had not been coated to keep loose pieces on the specimens. Once the records were mostly complete, I photographed the rocks so that their records would show what they looked like, making them easier to find in the future. 

One of the most important things to know about a rock specimen is where it came from (i.e., site, latitude/longitude, and formation). This allows us to identify its age and specific type. Having this data also provides more researchable information about what geological and environmental processes were occurring on Earth at the time of the rock’s formation. I checked the donation files for site information before doing extensive online research to complete the collection site and paleontology or geology fields in the database.

Depending on their use, rock and fossil specimens are defined as either artificial (think arrowheads, building materials, and statues) or natural (unmodified by humans).

The diversity of rocks and fossils found in North Dakota is truly amazing, and I got to experience that firsthand during my inventory of the rocks held by the State Historical Society. I found sandstone, granite, mudstone, limestone, petrified wood, plant and animal fossils, and fossils that were a combination of plant and trace fossils. 

Quartz syenite riprap from Fort Abraham Lincoln State Park in Mandan. Riprap are large rocks used to protect structures at shorelines from weathering and erosion.

Leaf fossil in a sandstone collected in North Dakota from a rock formation in the Fort Union Group, which formed during the Paleocene epoch (66 to 56 million years ago).

Clam fossil with mineral formation inside the cavity found at Long Butte, North Dakota, in the Sentinel Butte Formation. This specimen is from the Thanetian Age in the Paleocene epoch (59 to 56 million years ago), a time when North Dakota was covered by the ocean.

Looking for information on this scapula from a mammoth or mastodon turned out to be quite the scavenger hunt. The reference number on it was incorrect (the number actually belonged to a serving ladle), and we searched for days through the digital and physical records to find any trace of the object in the museum’s recorded history.

I have a geology background, which made this inventory especially exciting for me. One of the most interesting and coolest fossils I found in my inventory was a mudstone with opalized ammonites embedded inside. This occurs when silica spheres in the rock are slowly moved through the cracks of the shell replacing the organic material. These leave behind opal giving the fossils an iridescent quality not evident in most other minerals. 

Opalized ammonite fossils inside gray mudstone.

Another fascinating fossil was the North Dakota state fossil, Teredo petrified wood, which results when a tree is living in an aquatic or semi-aquatic environment and becomes infested with Teredo worms. As the landscape changes and the tree dies, the wood petrifies, and the worm tunnels are evacuated. While petrification is occurring, minerals become trapped in the tunnels and leave behind permineralized trace fossils where the worms burrowed. 

Permineralization occurs when tiny mineral pieces seep through the cracks and fill all the holes and crevices within the fossil, surrounding rather than replacing the organic material. Trace fossils are the tracks, trails, and tunnels left behind by organisms. When a tunnel gets filled with minerals from the surrounding rock, it becomes a permineralized trace fossil.

Teredo petrified wood is North Dakota’s state fossil.

An inventory can reveal the wonders of the objects that are in the museum collection. Even more fascinating is an inventory about rocks and fossils since it gives you the chance to read the history of the region and the planet. The rocks tell us that North Dakota used to be a marine environment before the water retreated and became a swamp that eventually dried out and transformed into the grassland of today. Rocks and fossils need to be preserved so we can continue to study our world’s rich history.

Spring has sprung, and we’ve been busy at the Pembina State Museum. Besides the usual spring cleaning, we are renovating spaces and preparing for spring and summer programs. This summer season promises to be an exciting one as we focus on an expanded schedule for Gingras Days in conjunction with Walhalla’s 175th celebration and on developing new programs that will be available at the museum.

We’ve already finished one of our renovation projects, updating the restrooms, and visitors can enjoy the improved bathrooms when they visit. Since the museum was first built in 1996, the restrooms had been a boring sea of beige. But now they are bright and colorful and so much more pleasant. The new design was inspired by the Hudson’s Bay Point Blanket with its four colored stripes of green, red, yellow, and indigo, an iconic part of the northern Plains fur trade.

This capote at the Pembina State Museum, which was made from a Hudson’s Bay Company Point Blanket, is part of our “Hands on History” display and helped inspire the restroom revamp.

We replaced the stalls, painted the ceiling, and installed new lighting. The lighting was installed first, and that improvement alone was stunning. Once the color was added and the space steam-cleaned by the contractors, the restrooms felt completely new. These pictures show the dramatic nature of the change.

The men’s room before, top, and after the renovation.

With the bathroom project complete, our attention now turns to program and event planning. “Arrows and Atlatls,” a pre-historic hunting program, is slated for introduction later this year. Atlatls, for the uninitiated, are spear throwers. The word “atlatl” derives from the Nahuatl (or Aztec) word for this ancient hunting device, found world-wide during Neolithic times. It was gradually replaced on the northern Plains by bows and arrows, with the bow appearing around A.D. 600. The atlatl had been in use for many millennia, but the bow was around for less than one millennium before Europeans introduced muskets. While visitors to the Pembina State Museum can try out our atlatl at any time weather permitting, “Arrows and Atlatls” will provide an in-depth experience for students and visitors.

Our atlatl, soon to be joined by others, is always available for visitors to try out. Just ask for a team member at the front desk to help you get started.

The objective of “Arrows and Atlatls” is to show students the advantages and disadvantages of pre-contact hunting technologies and to let them try their hand at using the tools themselves. This summer we will have scheduled atlatl demonstrations, where visitors can also participate. A few large animal targets will be available as well. Be on the lookout for a bear or bison decoy lurking around the museum.

The big event of the summer, though, is going to be the Gingras Days at the Gingras Trading Post State Historic Site near Walhalla. We are working with the Walhalla Area Chamber of Commerce to plan an amazing two-day event to coincide with the city’s 175th celebration. This will take place on July 1-2 and will include live music, vendors, and other programs.

Ryan Keplin, also known as “Fiddling Lefty,” will perform in the Walhalla parade on the morning of July 1 and then take his show over to the Gingras Trading Post for an afternoon performance of live music and folk tales. There’s no charge for admittance and anyone interested in Métis fiddle music is encouraged to attend. Vendors will also be on-site. Regional craftspeople will be on-hand selling various souvenirs and gifts.

On July 2, the Gingras site will once again be open with activities available all day. We will have “Games of Pembina’s Past” available for people to play both days of the celebration. These include grace hoops, hoop-and-stick, and trundling hoops. (Suffice to say, a lot of hoops are involved!) The house and trading post will be open both days for tours. The storeroom of the trading post will be set up with crafts on July 2. Bring the family and make your own popsicle stick ox cart. The “Red River Rendezvous” hands-on activity will also be set up in the trading room with new features representing life during the fur trade era of the early 1800s in the Red River Valley. Visitors will have the opportunity to try on a capote, a top hat, and snowshoes, and even set a trap with help from staff.

The Gingras trading room during last year’s Gingras Days. This year’s celebration promises to be even better.

These are just the plans solidified so far. More is still in the works, including improved shelving for on-site storage and the much more exciting, and relevant for visitors, improvements and programs planned for the updated conference room. The summer season promises to be very busy and very exciting!