1900 Hillsview Township, McPherson County, South Dakota =======================================================
Spietz, Andreas, b. Aug. 1867, age 32, married, 9 years, b. Wisconsin, parents b. Germany, teacher Spietz, Minnie, Wife, b. May 1869, age 31, married, 9 years, 4 children born, 4 children living, b. Kanada-Eng, parents b. Kanada-Eng., emigrated 1889 Spietz, Elma, Daughter, b. Aug. 1891, age 8, single, b. South Dakota Spietz, George, Son, b. Mar(?) 1894, age 6, single, b. South Dakota Spietz, Grace E, Daughter, b. April 1896, age 4, single, b. South Dakota Spietz, Pearl, Daughter, b. April 1898, age 2, single, b. South Dakota
Given that the enumerator was German (Johan Bauer), I would suspect that the spelling of the surname is probably correct.
In part of Alberta did they settle, as they don't seem to appear in the 1906 census?