DCHP-1 Online
prairie level 
See 1952 quote.
- 1873 (1904) The depression, or slope, of the prairie level toward the north continues, with marked regularity, throughout the whole of British America.
- 1884 Beyond this region, distinguished for the almost inexhaustible fertility of its soil, we cross the Second Prairie Steppe, which has an elevation of 1,600 feet above the sea level.
- 1952 From east to west these are . . . the Manitoba Lowland or First Prairie Level, with an elevation of less than 1,000 feet above sea level . . . the Saskatchewan Plain or Second Prairie Level, with an average elevation of 2,000 feet above sea level . . . the Alberta Plain or Third Prairie Level, which rises gradually from about 2,500 feet above sea level to nearly 4,000 feet at the foothills of the Rocky Mountains.
- 1963 They were now near . . . the long, low hill that is the edge of the next upward prairie "step."
- 1873 (1904) The depression, or slope, of the prairie level toward the north continues, with marked regularity, throughout the whole of British America.