Well what the heck, why not start a list. Here's a start. You know the drill -- copy, paste and add your favorites:
Scuba Diving Quarries in the United States
(and similar fresh water diving sites)
Alabama
Blue Water Park (Pelham, AL - south of Birmingham)
Dive Land Park (Glencoe, AL)
NASA Scuba Experience (Huntsville, AL)
Georgia
Kraken Springs (White, GA) - temporarily closed
Illinois
Haigh Quarry (Kankakee, IL)
Kentucky
Pennyroyal Scuba Center (Hopkinsville, KY)
FRP The Quarry (LaGrange, KY)
Missouri
Bonne Terre Mines (~1 hour south of St. Louis, MO)
Nevada
Lake Mead (Boulder City, NV)
New Mexico
Blue Hole (Santa Rosa, NM)
Ohio
Portage Quarry (Bowling Green, OH) - Closed
Gilboa Quarry (Ottawa, OH)
Natural Springs Resort (New Paris, OH)
Nelson Ledges Quarry (Garrettsville, OH)
White Star Quarry (Gibsonburg, OH)
Pennsylvania
Dutch Springs (Bethlehem, PA)
Willow Springs Park (Richland, PA)
South Carolina
Lake Jocassee man-made lake (near Salem, SC)
Lake Thurmond (Clarks Hill, SC)
Tennessee
Gray Quarry (near Johnson City)
Loch Low-Minn (Athens, TN)
Martha's Quarry (Mt. Juliett, TN - outside of Nashville)
Philadelphia Quarry (Philadelphia, TN)
Texas
Athens Scuba Park (Athens, TX)
Blue Lagoon (Huntsville, TX)
Windy Point Park (Lake Travis, near Austin, TX)
The Meadows Center (San Marcos, TX)
Reveille Peak Ranch (Burnet, TX)
The Scuba Ranch (Terrell, TX)
Utah
Homestead Crater (Midway, UT)
Virginia
Lake Phoenix (Rawlings, VA)
Washington
Titan Missile Silo (Royal City, WA) - currently diving suspended
Wisconsin
Wazee Lake (Black River Falls, WI)