In The Round House, why can't Geraldine remember where the attack was?

The main problem with Geraldine's recollection of her assault in The Round House is that the land is divided up so roughly that she can't identify what type of land she was on at the time. She knows clearly that it occurred near the Round House, a religious structure on the Indian Reservation, but because of the differing claims to the land, she is unsure whether the location of the attack was federal land, state land, or reservation land.
These different types of land have very different laws governing them, which make prosecution and legal matters very difficult. An attack on reservation land may be dealt with solely by leaders of the tribe, whereas state or federal land will be presided over by the authorities of that level of government, meaning the treatment of the case could vary wildly and the punishment handed down could also be entirely different depending on the jurisdiction.