The diversity of plant and animal life on the prairie at Jeffers provided a home for people to thrive in for millenia.
Minnesota covers the northeastern edge of a tallgrass prairie that once covered 400,000 square miles of North America. Today, less than one percent of that prairie remains. Of the 160 acres at Jeffers Petroglyphs, 33 are native prairie and 47 contain one of the first prairie restorations in Minnesota. An additional 80 acres were restored from farmland to prairie in 2004.
Like all prairies, this landscape is a mixture of flowers and grasses. More than 300 species of prairie plants are found at Jeffers Petroglyphs, some of which are very rare. A federally threatened species, prairie bush clover, thrives here.
This grassland is unique in other ways. Prairies are classified as wet, mesic, or dry. Because of the rock formation, all three types of prairie are found at Jeffers Petroglyphs. Wet prairies have considerable water in the soil, dry prairies have little moisture, and the amount of moisture in mesic prairies falls between the other two. Near the rock outcropping, the soil is shallow and dries out quickly, creating an environment perfect for plants adapted to the drier plains of the American West. Here you will find prickly pear cactus, buffalo grass, and little bluestem.
Because the rock face sheds water and concentrates it into a single area, a wet prairie environment dominated by cordgrass and sedge is also present. However, the prairie at Jeffers is primarily a mesic prairie, ruled by big bluestem and Indian grass that grows up to eight feet high.
The prairies in this region developed during a warm and dry period 9,000 years ago, a few thousand years after the last glaciers receded from the area. Prairie grasses and flowers adapted to these conditions by forming extensive underground root systems. With this adaptation, the prairie was able to survive fires, which were sometimes started on purpose by people to draw bison to the renewed, richer, shorter, tender grass that follows a fire. During wet years, these fires kept water-hungry trees from taking over the grasslands.
Although the diet of Native Americans consisted of a variety of plants, fish, insects, reptiles, and mammals, bison provided the essential dietary and raw materials needed to survive. They supplied food, clothing, bedding, shelter, fuel, tools, weapons, household utensils, personal or ceremonial adornment, and symbols of worship.
One bison provides hundreds of pounds of meat. Its tough, impermeable skin is ideal for making the mobile tipi, clothing, bedding, rope, shields, boats, bags, pipe holders, and parchment for painted records. Tools are made from bone. Thread is made from sinew. Cups are made from the horn. The stomach is used as a container for water and, when propped upright with four sticks, it becomes a pot for cooking with heated stones. The bladder is used as a water container and as a bag to store food.
In addition to providing direct sustenance for the bison, the prairie offers Native Americans foods such as prairie turnip, grass seeds, and rose hips, the same foods eaten by early immigrants of the 19th century. In the 20th century, prairies produced hay to fatten cattle, milkweed pods for food during droughts of the 1930s, and milkweed fluff to fill life preservers during World War II.