United States Counties with most tornadoes per area

Tornadoes from 1950-2004. Data from SPC tornado database and Storm Data, modified where appropriate. It is possible that there may have been a transcription error during my calculations, so this is not intended to be an official list. This list excludes small Virginia independent cities where the small area makes this calculation more difficult to interpret.
RankCounty Tornadoes County Land Area (square miles) Tornadoes/ square mile
1Pinellas County, FL 117 280 0.418
2Galveston County, TX 100 399 0.251
3Lee County, FL 106 803 0.132
4Hall County, NE 70 537 0.130
5Oklahoma County, OK 90 708 0.127
6Sarasota County, FL 72 573 0.126
7Escambia County, FL 81 660 0.123
8Lafayette Parish, LA 33 270 0.122
9Hillsborough County, FL 127 1053 0.121
10Tulsa County, OK 68 572 0.119
11Harris County, TX 205 1734 0.118
12Denver County, CO 13 111 0.117
13Adams County, CO 144 1235 0.117
14Union County, NJ 12 103 0.117
15Hale County, TX 117 1005 0.116
16Cleveland County, OK 57 529 0.108
17Nueces County, TX 91 847 0.108
18Gregg County, TX 29 273 0.106
19Jefferson County, TX 99 937 0.106
20Brevard County, FL 105 995 0.106