What marathon did the first woman officially finish, based on the paragraph.

For a long time after the Olympic marathon started, there were no long-distance races, such as the marathon, for women. Although a few women, such as Stamata Revithi in 1896, had run the marathon distance, they were not included in any official results.[32][33] Marie-Louise Ledru has been credited as the first woman to complete a marathon, in 1918.[34][35][36] Violet Piercy has been credited as the first woman to be officially timed in a marathon, in 1926.[32]

Arlene Pieper became the first woman to officially finish a marathon in the United States when she completed the Pikes Peak Marathon in Manitou Springs, Colorado, in 1959.[37][38] Kathrine Switzer was the first woman to run the Boston Marathon "officially" (with a number), in 1967.[39] However, Switzer's entry, which was accepted through an "oversight" in the screening process, was in "flagrant violation of the rules", and she was treated as an interloper once the error was discovered.[40] Bobbi Gibb had completed the Boston race unofficially the previous year (1966),[41] and was later recognized by the race organizers as the women's winner for that year, as well as 1967 and 1968.[42]

The first marathon that a woman officially finished was the Pikes Peak Marathon, completed by Arlene Pieper in 1959.