Big Muddy Valley EarthCache

Big Muddy Valley is 60km long, up to 3kms wide & as much as 160m deep. It runs in a southeasterly direction from south-central Saskatchewan to north-eastern Montana into the Missouri River Basin. At the end of the last ice age the Big Muddy was part of an ancient glacial melt water channel that carried vast quantities of water southeastward. Currently the only significant surface water in the valley is found in Big Muddy Lake & creek, which all but disappear in a dry summer. Big Muddy Lake is a shallow large alkali lake that sits 140m below the surrounding landscape. Big Muddy Creek flows through the valley & Big Muddy Lake then into the US where it meets the Missouri River basin.

The walls of the Big Muddy reveal the sedimentary layering process that created them over a series of geological periods beginning 65 million years ago. Each layer, called a formation, formed at a different time under different conditions. The youngest formations are found higher in the hills. Sedimentary rocks typically form in large bodies of water & over vast amounts of time as rivers ceaselessly deliver massive amounts of sand, silt, & clay into them. These particles are, in turn, distributed by bottom currents, tides, & waves until they eventually settle out as layers of sediment. The grain size of the rock indicates the environment in which the sediments were deposited. For instance, gravels are only deposited by fast moving streams, while fine clays are deposited in still water. As new layers accumulate, they compress the earlier layers with their weight, & cause them to lithify.

During the Cretaceous period 3 distinct layers of sedimentary material was carried from high regions to the west & deposited over southern Saskatchewan. The 1st of these sedimentary layers is known as the Bearpaw Formation. It is characterized by dark marine shale, layers of bentonite & sandstone tongues & it often exceeds 335m in thickness. This layer forms the subtract material to the north of the Missouri Coteau.

The 2nd sedimentary layer is the Eastend Formation which shows a transition from marine to fresh water. It is characterized by rusty green to yellowish siltstones, sandstones & mudstones. The upper layer is kaolinzed. Kaolin is exposed in the valley near Castle Butte & Highway 34. Although of poor commercial quality, the coal seams found in the Eastend Formation were mined for local use in the early part of the 20th century.

The 3rd sedimentary layer is known as the Whitemud which is non-marine & varies from 0 to 14m in thickness. The white kaolinitic material along with the gray to black layers of carbon make it easy to recognize. The Whitemud Formation is the most important source of ceramic clay in Western Canada, supporting the local pottery, pipe, brick & clay industries.

During the Paleocene period, the Ravenscrag formation was deposited up to 160m thick in the Big Muddy Valley. It is characterized by coal beds, nonmarine sands, shales, silts, & clays. Where exposed on a cliff face the lower edge is grey in color & is called the "grey facies". The upper layer is brownish often containing white kaolinitic Willow Bunch member material. This layer is called the "buff facies".

In the Miocene period a coarse gravel crossbedded sand layer was deposited as a thin sheet over the Ravenscrag Formation. The layer deposited in the Miocene era was known as the Wood Mountain Formation. The formation consists of largely unconsolidated gravels & sands with local occurrences of lithified conglomerate & sandstone.

The Pleistocene period was the last ice age & it changed this area forever. To the north the ice sheets were much thicker but to the south they were non existent. As the melt water was channeled it carried vast quantities of water eastward. Sediment was deposited forming deltas of fine silt & sand. Flat outwash areas formed flat fertile land. The town of Bengough is built on one of these outwashes. Terminal, ground & hummocky morrianes formed the major landscape characteristics around the valley. In the recent period erosion has served to round the hills, cut channels, & in general deposit material in the valley. This results in an area of spectacular yet harsh beauty.

The Big Muddy landscape is fascinating ranging from smooth, rounded, rolling hills covered with natural grass to the far more dramatic rugged buttes, cliffs & hogbacks which reveal the sedimentary layers of this valley. The most famous natural features include Castle Butte, The Three Sisters, & The Arch. Because of this diversity, the flora & fauna of the area are also very diverse. Vegetation in the region includes prickly pear cactus, greasewood shrub, Woods rose, Western Red lily, sage, & a grey-leafed bush known as wolf willow. There are also many species of wild fruit trees including chokecherry, saskatoon, pincherry, buffalo berry, raspberry, currant, gooseberry & rosehip. Trees are deciduous except for juniper & creeping cedar shrubs. Animal species are numerous as well including Golden Eagle, bat, coyote, badger, raccoon, weasel, whitetail deer, mule deer, antelope, red fox, cottontail & jackrabbit, gopher, lynx, bobcat, turkey vultures, prairie falcon, piping plover, upland game birds & waterfowl. There are a wide variety of hawks, including Ferruginous, Cooper's, red-tailed, pigeon, sparrow, marsh & Swainson's. There are rare sightings of the Prairie rattlesnake, although it is found more commonly to the west. Other common reptile sightings are garter snakes, Eastern Yellow-bellied Racers, Smooth Greensnakes, very large bull snakes, toads, frogs, & turtles. Also in this region are the endangered Burrowing Owls.

The Big Muddy is unique to Saskatchewan. There have been several earthquakes in the area with the largest being in 1909, measured by a seismograph in Ottawa at a 5.5 magnitude. Several seismographs were installed in 1965 & have recorded 14 earthquakes since. Also unique is that the area is rich in paleontological finds. In 2001 a 2m skeleton of a 60 million year old crocodile was found there. There is nowhere else in SK with both fossils & quakes The Big Muddy is also rich in history & lore.The land of legendary outlaws, medicine wheels, massive ranches, ceremonial circles, stone effigies & undisturbed buffalo jumps. With Plains nomadic societies visiting as far back as 10,000 years ago there are numerous teepee rings, cairns & other ceremonial boulder arrangements throughout the Big Muddy. Some of the most seen effigies are Turtle Effigy, Medicine Wheel, Buffalo Effigy (only known one in Canada), Bird Shoot Effigy. Towards the end of the Indian occupancy & before this area became settled, it went through a phase of outlaw history.

Because of its location near the US border, the Big Muddy attracted bandits & horse thieves needing refuge. Patrolling the region was a challenge for the NWMP because local ranchers, who wanted no trouble, often turned a blind eye to illegal activities. Some of the colorful characters were Sitting Bull, Butch Cassidy & the Wild Bunch, Sam Kelly Gang, Nelson-Jones Gang, Dutch Henry, Coyote Pete, & Frank Carlyle. Butch Cassidy set up The Outlaw Trail extending from Station #1 in the Big Muddy to Mexico with stops and fresh horses every 25kms. The NWMP established a post here in 1902 but the harsh geography of the Big Muddy made the Mounties task of patrolling the area very difficult. With the end of the outlaw era the last RCMP horse patrol was in 1938. Tours are available from Coronach if you wish to learn more about the history of this area.

The cache rating is due to the remoteness of the area. We don't recommend attempting this cache when its wet as things are very slick. You do not need to climb the butte to log this cache so when you are at the site the rating is quite low. Although if you want to climb the butte there is a steep path to the top but please be careful. The view from up top is spectacular! There are some neat natural cave near the bottom of the butte that you can explore as well. As always respect the environment and practice Leave No Trace Ethics.

Here is a GLOSSARY of some terms used above:
BENTONITE: clay formed by the decomposition of volcanic ash that can absorb large amounts of water expanding several times its normal volume
CONGLOMERATE: rock consisting of pebbles embedded in a finer cementing material
CRETACEOUS PERIOD: from 140million-65million years ago, characterized by greatest development & subsequent extinction of dinosaurs & advent of flowering plants & modern insects
FACIES: rock/stratified body distinguished from others by its appearance or composition as it reflects conditions & environment when deposited
GROUND MORRAINE: till covered areas with irregular topography & no ridges forming gently rolling hills/plains. Accumulates under ice by lodgement/deposition as glacier retreats
HUMMOCKY MORRAINE: formed by the "pressing" of fine-grained glacial debris under overburden pressure till deformation below stagnant thinning ice
KAOLIN: fine clay used in ceramics & refractories & as a filler/coating for paper & textiles
KAOLINITE: very common mineral, hydrated aluminum disilicate, formed by alteration of other minerals
KAOLOINIZE: minerals containing kaolinite are weathered, converting mineral into Kaolin.
LITHIFY: to change sediment to stone
MIOCENE PERIOD: 25-10 million years ago, when grazing mammals became widespread
MISSOURI COTEAU:narrow band of prairie uplands stretching across southern Sk to South Dakota, characterized by low hummocky, undulating, rolling hills, potholes & grasslands, unsuitable for agriculture
MORRAINE: any formed accumulation of unconsolidated debris usually soil & rock caused by a glacier from an ice age
MUDSTONE: fine-grained, consisting primarily of compacted, hardened silt & clay, where proportions of silt & clay are about equal
NWMP: North-West Mounted Police
PALEOCENE PERIOD: 65-55 million years ago, characterized by a proliferation of mammals, & continental collisions
PLEISTOCENE PERIOD: 2 million years ago to 10,000 years ago, characterized by widespread glacial ice & advent of modern humans
Sandstone: Lithified sand particles
SILTSTONE: lithified silt particles
SHALE: lithified clay particles
TERMINAL MORRAINE: characterized by debris ridges formed at the end or snout of the glacier by debris carried from the top of the glacier to the bottom