http://olympstats.com/2017/09/21/usa-olympians-and-their-colleges/
In fact the four leading schools, in terms of number of athletes, are: 1) Stanford, 2), UCLA, 3), USC, and 4) Cal Berkeley.
COLLEGE ATHLETES GAMES MEDALS RANK
Stanford University 289 408 282 1
UCLA 277 394 241 2
Southern Cal 251 357 228 3
U Cal Berkeley 212 283 201 4
Harvard University 210 276 121 5
Yale University 149 187 113 6
University of Michigan 145 189 131 7
University of Minnesota 140 191 68 8
University of Pennsylvania 131 166 71 9
University of Colorado 128 189 27 10