How? His bloodline.

Black Bear and his partner of nine years, Jason Pickel, plan to walk each other down the aisle Thursday, surrounded by family and friends, before signing a marriage license granted by the Cheyenne Arapaho Tribes. Black Bear, 45, is a member of the Oklahoma-based tribe, which is among the few Native American tribes in the US that allow same-sex marriage.

Like all federally recognized tribes, the Cheyenne Arapaho can approve laws for its land and members. Its code regarding marriage doesn't address gender, referring to the parties simply as "Indians", and requires that one person be a member of the tribe and reside within its jurisdiction.