Here are the materials in Poor Bear v. Jackson County (D. S.D.):
29 Statement of the Interest of the US
Complaint here. Other materials here.
News coverage here.
UPDATE: I should point out this doesn’t look like a formal motion to intervene, more like an amicus brief.
Here is the pleading in Poor Bear v. County of Jackson (D. S.D.):
The complaint is here.
Here is the complaint in Poor Bear v. County of Jackson (D. S.D.):
An excerpt:
This case arises from Defendants’ refusal to establish a satellite office for voter registration and in-person absentee voting in the Town of Wanblee on the Pine Ridge Reservation, thereby making voting less available to Native Americans in Jackson County in violation of Section 2 of the Voting Rights Act of 1965 and the Fourteenth Amendment to the United States Constitution. Specifically, because in-person voter registration and in-person absentee voting are limited to the county seat of Kadok, Native American residents of Jackson County are required to travel, on average, approximately twice as far (and such travel takes approximately twice as much time) to take advantage of in-person registration and in-person absentee voting in comparison to white residents of Jackson County. Establishing a satellite office in Wanblee, on the other hand, would substantially reduce the distance and travel time for both groups, would essentially equalize the average travel time and distance for the two groups, and would thereby provide Native Americans an equivalent level of access to in-person registration and in-person absentee voting.
Turtle Talk 