Boulder monuments are patterns traced upon virgin prairie utilizing glacial till boulders to define a desired outline pattern. The boulders most commonly used range from 10cm (4 inches) to 40cm (16 inches) in diameter. In Saskatchewan the boulders are most commonly smooth quartzite or granite cobbles, although some dolomites (limestone) and feldspar stone varieties have been used. In Saskatchewan these monuments extend from the Alberta border to the Manitoba border and from the Prince Albert area south to the international boundary. An additional 200-300 of these monuments have been recorded on the Great Plains beyond Saskatchewan's borders. Their extent across the northern Great Plains ranges from the Rocky Mountain foothills in Alberta, Montana and Wyoming east to Manitoba, Minnesota and Iowa. In Alberta and Saskatchewan they extend south from the region of the 53rd parallel into central Nebraska. Additional boulder outline designs have been recorded as far away as the northern Baja peninsula, southeastern Texas, and central Ontario; however, none of those patterns are deemed to relate to the monuments recorded within the Great Plains/short-grass prairie environment.
The monuments commonly depict the location of a specific sacred ceremonial activity (see figure, image at left: medicine wheel near Oxbow), an environmental site marker (see figure, image second from left: salamander outline near Mankota), an offering between an individual and his Creator (see figure, image second from right: human figure near Mantario), or the location of a specific ceremony (see figure, image at right: ceremonial circle near Claybank). Currently, 167 of these monuments have been recorded in Saskatchewan; however, only 33 have been mapped. The mapped examples include 11 medicine wheels, 10 ceremonial circles (circles too large in diameter to be considered habitational/ tipi ring structures), four human effigies, five animal effigies, and three geometric designs (special ceremony patterns). Medicine wheels are monuments that resemble a wheel pattern; the radiating lines of the pattern are referred to as the spokes. Associated piles of rock are called cairns, while circular patterns of stones are referred to as circles; these latter patterns may be transected by the spokes, or form an encompassing exterior boundary to the monument. Additional research has further subdivided medicine wheels and ceremonial circles into more categories that have been compared with specific First Nations' cultural ceremonies, although the different categories may reflect many different cultural groups. The four medicine wheel designs may identify: burials - a central cairn with a minimum of four radiating spokes; surrogate burials - the location where a leader died but was not buried is represented by four spoke lines, without a central cairn structure; medicine hunting structure - a large central cairn with a minimum of four radiating spokes which dissect an encompassing boulder circle, where the spokes terminate at small cairns; and a fertility symbol - a small central cairn with a minimum of four radiating spokes that all terminate at an encompassing boulder circle.
Ceremonial circles are either too large to be tipis (which range in size from 4m to 6m in diameter) or have features that identify them as separate from tipi rings. The four ceremonial circle designs theoretically represent a buffalo fertility symbol (a large central cairn with a pathway extending out to, or beyond a large encompassing boulder circle); a meeting circle, where the boulder circle measures between 18m up to 44m in diameter; a burial (a large central cairn encompassed by a boulder circle); or a ceremonial/dance oval (6m wide and 18m long transected by an interior boulder line, which ends within 2m of one edge). The four human effigies can be positively identified as two males and two females. The animal effigies are identified as two turtles, a badger, a bison and a salamander. The geometric figures record a special sacred site, a resource marker and a raiding shelter.
The first of these outlines was recorded in what is now Saskatchewan in 1864 by William Clandening, an explorer from eastern Canada. The second discovery was mapped and excavated by Henry W. Montgomery, of Illinois, in 1907. Beginning about 1954, the Saskatchewan Museum of Natural History, now the Royal Saskatchewan Museum (RSM), began a program of detailed mapping and recording of all the known boulder monuments. This practice was continued into the late 1980s, when the recording aspects were transferred to the Heritage Resource Management branch of the Department of Culture, Youth and Recreation. Only one of the two excavated medicine wheels in Saskatchewan has supplied datable samples: the Moose Mountain medicine wheel has tentatively been dated as about 1,300 years old. Additionally, three Alberta medicine wheels have been tentatively dated as 1,600 years old, 120 years old, and 60 years old. The latter two dates record a possible tradition continuance. The two earliest dates were based upon radiocarbon dating analysis, while the two recent dates were recorded by recent oral history. A lichenometric dating attempt was initiated by the RSM in 1980; however, as lichen diameters increase extremely slowly, that analysis may not produce results for another twenty years.