Most tornadoes in a single state in a 24-hour period

Last updated: 5/26/2014 and are believed to be valid through 2013.
UNOFFICIAL! I believe this to be accurate, but I may have missed something.
Number State Beginning time of 24-hour period
72 Oklahoma 3:00 pm CST, May 3, 1999
72 Tennessee April 27, 2011
70 Kansas May 23, 2008
68 Texas 3:00 am CST, September 20, 1967
63*South Dakota June 24, 2003 [Note: 66 tornadoes listed in SPC database, but only 63 found in Storm Data]
62 Alabama April 27, 2011
55*Arkansas 3 pm CST, January 21, 1999 [Note: perhaps 57]
55 Oklahoma May 10, 2010
48 Minnesota June 17, 2010
45 Alabama April 15, 2011
44 Kansas April 14, 2012
41 Kansas 3:15 pm CST, June 15, 1992
41 Missouri 9 am CST, March 12, 2006
40 Mississippi5 pm CST, April 26, 2011
Data based on SPC tornado database and Storm Data.