S. 105 is a bill that aims to allow certain land on the Pine Ridge Indian Reservation in South Dakota to be held by the Oglala Sioux Tribe and Cheyenne River Sioux Tribe in "restricted fee status." This means the tribes will own the land and it cannot be sold without Congress...
Simple Explanation
The bill lets the Oglala Sioux Tribe and Cheyenne River Sioux Tribe in South Dakota own special land that is very important to their history, and this land can't be sold or taxed easily. They have to follow some rules, like no building casinos there, and the people in charge need to make sure everything is set up within a year.