I received an email with the information from DowntownOkc.com

A Grand Opening will be held Friday March 30th at 2:00 p.m.

The location will be in the UNDERGROUND below the 101 Park Avenue building off of Broadway between Main and Park.

Entry locations are in the Broadway Kerr parking garage, Skirvin Hilton at the Santa Fe parking garage & First National Center with parking at the Main Street parking garage.