Bob - here's what I came up with - it's from 2002, so I don't know how accurate it is these days:

Isle of Capri Location Numbers:
10 Bettendorf, IA
11 Lulu, MS
12 Marquette, IA
13 Natchez, LA
14 Kansas City, MO
16 Rhythm City, IA
17 Boonville, MO
20 Biloxi, MS
30 Vicksburg, MS
40 Bossier City, LA
43 Bossier City, LA (old number)
50 Lake Charles, LA
55 Crown Plaza, Biloxi, MS (old number)
60 Davenport, IA
68 Misc. locations (Black Hawk, Vicksburg,

Enchanted Capri Cruise Ship – old numbers)
70 Pompano Beach, FL
80 Black Hawk, CO
90 Tunica, MS
109 Lake Charles, LA (old number)