Oskaloosa is a city in and the county seat of Mahaska County, Iowa, United States. In the late nineteenth and early twentieth century, it was a national center of bituminous coal mining. The population was 11,463 in the 2010 census, an increase from 10,938 in the 2000 census.HistoryOskaloosa derives its name from Ouscaloosa who, according to town lore, was a Creek princess who married Seminole chief Osceola. A local tradition was that her name meant "last of the beautiful." (This interpretation of "last of the beautiful" is not correct. "Oskaloosa" in the Mvskoke-Creek language means "black rain," from the Mvskoke words "oske" (rain) and "lvste" (black). "loosa" is an English corruption of the Mvskoke word "lvste". See for example the Wikipedia entry for Tuskaloosa, eponym of the town of Tuscaloosa, Alabama. In addition the Mvskoke word "Ouscaloosa" means "Black Water"). The first European-American settlers arrived in 1835, led by Nathan Boone, youngest son of frontiersman Daniel Boone. Acting on instructions from Stephen W. Kearny, he selected this as the first site of Fort Des Moines, located on a high ridge between the Skunk  and Des Moines rivers. The ridge was originally called the Narrows.