US attorney filed the ADA complaint

http://rapidcityjournal.com/news/local/mystery-solved-us-attorney-requested-arena-inspection-on-ada-issues/article_4c784e69-d7d4-59b6-8a17-06d21026e1de.html

"Johnson said Monday it was because of him. Not only had he heard concerns from Rapid City residents, he said, but he’d also personally noticed accessibility issues in the arena. Johnson’s father, Tim, a former U.S. Senator now retired from a long political career, uses a scooter because of stroke-like mobility problems caused by a cerebral arteriovenous malformation.
'I can’t speak for other U.S. attorneys, but I can just speak for myself,' Brendan Johnson said. 'I’ve got a problem with facilities in South Dakota that aren’t handicap-accessible.'
Johnson said he personally contacted officials at “main DOJ” — Justice Department headquarters in Washington, D.C. — sometime prior to August 2012 and asked them to conduct an evaluation of the arena’s ADA accessibility.
Back in February 2012, six months before the arena inspection, Pennington County, of which Rapid City is the county seat, had already been notified that it was selected for an ADA review as part of Project Civic Access, a program of the Disability Rights Section of the Justice Department’s Division of Civil Rights. In that program, locales are selected for ADA compliance reviews as part of an effort to spread compliance across the nation, oftentimes without any formal complaint to instigate the reviews.
Jeff Stroot, human resources director for Pennington County, said the multi-day compliance review specifically targeted Pennington County-owned facilities. He was not aware that the review would include the city-owned arena, and he didn’t learn until later that the arena had been inspected.
Why did the inspection team members venture over to the civic center? Johnson suspects his request had filtered down to them."

But I don't think anybody is trying to stop the ADA fixes.  Both sides agree this must be done.  What there seems to be no agreement on is the cost.  This article says $40 million. The mayor says $72 million. Another source says $36-38 million.