The federal Justice Department is investigating whether Rapid City's Rushmore Plaza Civic Center fails to comply with the Americans With Disabilities Act.
A complaint was filed in August, just weeks after a city economic development committee voted to explore spending up to $150 million to expand the 1977 building.
Mayor Sam Kooiker has argued since then for the need to bring the civic center into compliance with the ADA, which took effect in 1990. He says it's hard to defend not having a plan after 22 years.
A study done in 2004 estimated the cost of bringing the Civic Center into ADA compliance at $36 million. The city decided at that time to add an ice arena instead.