"Head Smashed In"... um, sounds like a great place to visit...

The High Plains have their quiet times. Sure, there are the vicious winter storms,  the days when the wind blows hard, and the summer thunderstorms. But other times the wind may be just a light breeze through the grass, maybe a hawk soaring overhead. Or a huge marmot standing guard on a sandstone outcrop. But I can also stand in this place and imagine a similar quiet day a few thousand years ago. It's quiet, but then the ground starts to tremble, and a dust cloud rises over the crest of the low hill. The birds startle and take flight, the marmot dashes for cover, and suddenly over the ridge comes a thundering herd of buffalo. They're stampeding, and the leading animals start to shift directions, but then suddenly a strange figure jumps up, yelling and waving limbs. It might be a wolf, it's hard to tell in the panic, so the herd shifts direction once more. The leaders now realize they are headed for a precipice and they try to stop, but it's too late. They go over the edge, pushed by the animals behind. They impact on the rocks and bones below, most of them dead immediately. In a moment it is over. People emerge from their hiding places and start to butcher and process the meat, bones and hides. It has been a successful hunt and they will have enough food and furs to make it through the difficult winter.

There is a seven story building in this picture. Can you see it?

The First Nations people of Canada and Native Americans of the High Plains depended on the buffalo for survival. They made use of the meat, the fat, the bones, and the hides. But anyone who has ever seen one of these immense animals knows that they would a dangerous adversary in a hunt. They can be as long as eleven feet and weigh a up to a ton. They can easily outrun a human, capable of speeds of 35 miles per hour. Though it was done, bringing one down was a difficult and dangerous proposition.

We were in southern Alberta on our Northern Convergence tour of western Canada, and were making our last stop in the country at Head Smashed In Buffalo Jump World Heritage Site. At Head Smashed In and similar localities, the geology provided a safer way to hunt the animals.

At the edge of the prairies where the mountains rise from the plains, the land is not so flat as it is further east. The convergence far to the west compressed and pushed up the Rocky Mountains. The soft Cretaceous mudstones and sandstones underlying the high plains were also pushed up into broad swales and low hills. Ice, water, and wind exploited fractures in the rock, and erosion ate away at the edges of the hills, exposing vertical cliffs of sandstone. Just such a cliff is exposed in the Porcupine Hills outside of Fort Macleod, Alberta. For at least the last 5,800 years, people have utilized the cliff here to capture and kill buffalo.

A spring emerged from the base of the cliff, providing water at the kill site (the green watercourse is visible in the picture above). The Old Man River flows in the flats below, providing sheltered sites for villages.

Tipis have become such a stereotype that some might think that most Native Americans lived in them. I groan inwardly whenever I see one at "Indian Stores" or southwest tourist traps. But the tipi at Head Smashed In was an appropriate sight. The tipis were an excellent shelter on the windy plains. They were portable, an important consideration for a nomadic people. I know of paleontologists in the region who tried to camp in modern nylon tents, but gave them up for tipis, which were more comfortable and more durable in windstorms.

The site was declared a World Heritage Site in 1981 for its archaeological value. Excavations 39 feet deep in the cliff show a complex history of buffalo hunting going back 5,800 years (two spear points show activity in the area as far back as 9,000 years. The visitor center was constructed to blend in to the landscape, and does so admirably (see the picture above). There are trails to the top of the cliff where some cairns from the hunts can still be found. A trail also loops around the base of the cliff. One of the nice surprises inside the well-designed center was a hallway lined with numerous paintings and artwork by First Nation students representing the oral histories of their culture.

About the name of the place. In the Blackfoot language it is called Estipah-skikikini-kots. Legend has it that a young man decided to watch one of the buffalo hunts from the base of the cliff. He picked a bad spot, and was crushed beneath the weight of the falling animals. The name doesn't exactly inspire confidence in the site as a destination when traveling in the region, but it is indeed a fascinating place to visit. It's full of history, but it is also a place of wide-ranging views and scenic beauty, and despite the name, serenity.

Northern Convergence: We'll Call it "Rock": The Okotok Erratic

There is a big rock out on the high prairie near Calgary, Alberta. That all by itself is a bit of strangeness. It's even more strange because it is around a hundred miles (160 km) from the cliff in which it originated, up in the Rocky Mountains in Jasper National Park. The Blackfoot Indians had a creative name for the rock, Okatok, which in their language means, um, "rock". These names always sound better in the original language! For whatever reason, the spelling changed a bit to Okotok.

The Blackfoot people had a great story for how the rock got to this spot, a myth that could have served as the inspiration for the rock monster in the movie "Galaxy Quest". Their legendary trickster Napi was resting on the rock on a hot day, so he left his cloak on the rock, saying "Here, I give you my robe, because you are poor and have let me rest on you. Keep it always". Murphy's Law dictates that it soon got cold, and the rain began, so Napi asked for the return of his robe. The rock refused so Napi grabbed "his" cloak. In a moment, the rock was up and running after him! Napi called on his animal friends, the Bison, Antelope and Deer, and none of them could stop the gigantic rock. When all seemed lost, a bat flew straight at the rock, collided with it, and the rock was split in two! The bat had saved Napi, and got a squashed face for all his trouble (such things have to be explained somehow...).*

A smaller erratic a few hundred yards from the Okotok Erratic

The geologists tell a different story, and were it not for the overwhelming evidence it would seem just as fantastical. During the Pleistocene Ice Ages, the continental ice sheets covered all of the region thousands of feet deep. Up in the Rockies at Jasper a huge rock slide dumped massive boulders onto the surface of the glaciers emanating from the high peaks. The glaciers flowed eastward onto the High Plains, eventually meeting up with the vast ice sheet that originated near Hudson Bay. The two ice sheets didn't mix, so the two "rivers" of ice flowed together towards the south. The gigantic rocks from the cliff in Jasper were dumped in a line many miles long where the glaciers moved together. These isolated boulders are called glacial erratics.

The rock is sometimes claimed as the largest erratic boulder in the world, but I have no way to evaluate the claim. It certainly is huge, and worthy of a visit (it is a few miles southwest of Calgary). The Blackfoot or other First Nation peoples were certainly impressed. Faint pictographs can still be seen on the flanks of the rock.

Pictographs are symbols painted on the rock. Petroglyphs are chipped into the rock.

This is a continuation of our Northern Convergence tour of British Columbia and Alberta. In this case, I guess "convergence" refers to the two masses of glacial ice. We concluded our visit and headed back towards the Rocky Mountains and Crowsnest Pass to check out a not-so-long-ago tragedy. More on that next time.

*The Blackfoot legend is  loosely rephrased from interpretive signs at the park.

A Convergence of Wonders, Day 8: Of Time, Pressure and the Plain Truth

Day 8 of our journey through the Pacific Northwest found us in a time of transition...we weren't exactly in the northwest anymore, for we had left the Rocky Mountains and were traveling southward across the Great Plains. With an important exception, the landscape had become more subtle and its geologic secrets were well-hidden. In a historical note, we were just a few miles south of the northernmost point reached by the Lewis and Clark expedition in 1805.

The archaeologists were interested in the fact that we had arrived in the ancestral lands of the Plains Indians, and indeed since we had left Glacier National Park, we had been on the Blackfeet Indian Reservation. The billboard that greeted us at the edge of town was an acknowledgement that we were in the home of a different culture.

Our first stop was Museum of the Plains Indians in Browning. The museum (which did not allow photography) was filled with exhibits of Native American arts, and is well worth a visit.

At Browning, the landscape was irregular, with numerous small hills and isolated ponds. The hummocky topography is the result of the passage of continental glaciers moving south out of Canada. As we drove south, the shape of the land became more "normal" (for us Californians, anyway), with gullies and valleys carved by stream erosion. The Rocky Mountains remained in sight, off to the west.

At the small village of Choteau, we paid a visit to their modest museum, and had a look at some dinosaur specimens, including the display below on dino eggs. The region around Choteau is remarkable for two reasons. Excavations started in the 1970s revealed numerous dinosaur nesting sites, which were used repeatedly for tens, maybe hundreds of thousands of years. Not only were the eggs themselves important, but also the behaviour of the dinosaurs that laid them. Work by Jack Horner and others demonstrated that the Maiasaurs took care of their young, and that they moved in herds.We didn't have the time to arrange a trip to nearby Egg Mountain, so we settled for the displays.

Outside of the town of Augusta, we headed west towards Sun Canyon for a look at some remarkable Rocky Mountain geology. That glaciers had once emerged from the canyon onto the plains was immediately apparent, as the road traversed the rocky slopes of the terminal moraines.

Soft Cretaceous sediments were apparent in the streamcuts. In the picture below one can see a sweet little anticline, an upward pointing fold. The mountains loomed higher and higher as we continued west. And something was odd about them...

As can be seen in the picture below, there are two sets of prominent cliffs at different levels. They are made of the same rocks! The geology was repeating itself. It wasn't just once. As we drove up the canyon, the same carbonate rocks were repeated at least five times.

What we were seeing was another manifestation of the extreme compressional forces that resulted from the convergence of the North American continent with the oceanic crust of the Pacific Ocean basin. In latest Cretaceous and early Cenozoic time (70-50 million years ago), the crust was disconnecting from the underlying basement rocks in a series of blocks that were sliding up and over each other in a series of overthrusts. At least twenty such thrusts occurred in this part of the Rocky Mountains, and we drove past five of them.

 The outcrops and the scenery were incredible...

An additional point of interest for us...the carbonate rocks formed in a shallow sea in Devonian and Mississipian time, and were full of fossils of marine life, like crinoids, brachiopods, corals, and bryozoans. The students spent some time searching for the evidence of past life.

As we drove back down the canyon, we were reminded why creeks and rivers were flooding all over Montana and the Great Plains. There was still a tremendous, even unprecedented amount of snow left in the high country, and small reservoirs, like Diversion Lake, seen below, were filled to overflowing. 

 Going down canyon, we were given a different perspective on the repeating structural blocks.

We made one more stop in the lower canyon, looking for some ammonites. We instead found these strange burrowing structures in the Cretaceous rocks. They were identified by my Twitter colleagues as Thalassinoides burrows, something akin to burrowing crayfish or shrimp. They were huge! That's a quarter at the top of the sample.

 Back on the plains, we were treated to a view of a curious pronghorn.

The day was getting late, and we were delayed by a radiator leak, but we eventually made it to camp in Bozeman, where I had a chance to meet up with a fellow geoblogger, Callan Bentley of Mountain Beltway. He's normally at Northern Virgina Community College near Washington, D.C., but was on the road getting ready for a field class he was teaching in Montana. It was a nice to finally meet!

For whatever monotony there was on the long road across the plains, it would be made up for in our next day's journey...we were headed for Yellowstone via the Beartooth Highway.