In January 1989, the school was sold to Lansdowne University Ltd., a South Dakota corporation with ties to a college in London.

In February 1992, Eastern International Education Association, a Delaware-based corporation headed by a member of the Japanese House of Representatives, purchased the school and set up a branch campus in Tokyo.

In December 1996, the Huron and Sioux Falls campuses were sold for $3.5 million to for-profit Whitman Education Group, Inc., then owners of Colorado Technical University (CTU).

The Huron campus became Si Tanka University-Huron, the first off-reservation university controlled by a Native American tribe.

The Tribe financed the deal with $6.6 million in loans and guarantees from the U.S. Department of Agriculture, but soon found it could not support the school.

The federal government grants that the Tribe had been counting on required at least 50% Native American enrollment, and Si Tanka couldn't meet that threshold with its new, primarily white Huron campus.

The situation was further complicated by a scandal in April 2002, when a freshman basketball player at Si Tanka was arrested and eventually pleaded guilty to intentionally exposing another student to the AIDS virus.

In February 2006, the Chapter 11 case was dismissed when a federal judge found there weren't enough remaining assets for unsecured creditors.

Two empty lots, including the football field, were sold immediately, but as of 2006, the bank was uninterested in selling buildings individually and continued to seek a buyer for the property as a whole.