There are 4 Petersons mentioned in the Fillmore County Book. They are Charles Peterson, Hans Peter Peterson, Lorenz Peter Peterson, and Walfred C. Peterson.
There is a map of the Fairmont Township Homestead Map, and his name is one of those owning a piece of property (this is on pg. 128). He is also mentioned on pg. 377 as being a member of the Fairmont branch of the Vigilant Society whose purpose was "to recover horses or mules and to detect and bring to punishment any person or persons who may steal a horse or mule or horses or mules from any member of this Society. . ."
Both Hans Peter Peterson and Lorenz Peter Peterson are mentioned only in a map of Belle Prairie Township Homestead Map as owning property (in adjoining plots).
Walfred C. Peterson appears in several pages. On pg. 74, it says "Walfred Peterson operated one of the first large threshing outfits in Chelsea township." It goes on to describe the details of threshing. On pg. 178, in an early automobile section, there is a listing of advertisements from the local paper of automobile dealers, including "W.C. Peterson and Co. -- Buick, Velie, and Jackson Automobiles -- Home of "Wife Getter Buggies". Then, there is a nice entry that takes up most of pg 88 detailing Walfer C. Peterson's life. He was born Sept. 23, 1866 in Kalmar, Sweden, married Rosalie Chaney on Oct. 1896. Their children were: Leta (Tomlinson), Dazel (Camp), John C., Rose L. (Hammond), Marion L. (Calder), Helen M. (Biba), Frank W., Paul L., M. Murle (Abrahamson).
There doesn't seem to be any mention of a Pleasant Ridge in Fillmore County. The following townships are included: Belle Prairie, Bennett, Bryant, Chelsea, Exeter, Fairmont, Franklin, Geneva, Glengary, Grafton, Hamilton, Liberty, Madison, Momence, Stanton, West Blue. In addition, the following post offices were listed (these never made it to official 'township' status): Dudley, Gazelle, Eden.
In a county next to Fillmore, there is a town called Pleasant Dale, Seward County. Perhaps it is this town that the scriber meant to say. Just a idea.