Let me Google that for you...
UT has done well in swimming (5 golds) with another gold in shotput.
WVU - 1 gold in 10m Air Rifle (isn't this a carnival game?)
OU - 1 silver (triple jump) and 1 bronze (pommel horse)
Colorado (former BigXII athletes) - 2 bronze in steeplechase and mile run
http://www.big12sports.com/ViewArticle.dbml?DB_OEM_ID=10410&ATCLID=209896624
The Big 12 Conference boasts a league-record 100 current or former student-athletes that will compete at the 2016 Summer Olympics in Rio de Janeiro, Brazil. The list includes those who competed in the Big 12 at some point in their careers or are/were student-athletes in a NCAA-sponsored sport when the institution was in the Big 12.
GOLD
Michelle Carter (UT) W Shotput
Jack Conger (UT), M 4x200m Free Relay
Jimmy Feigen (UT), M 4x100m Free Relay
Townley Haas (UT), M 4x200m Free Relay
Joseph Schooling (UT), M 100m Butterfly
Clark Smith (UT), M 4x200m Free Relay
Ginny Thrasher (WVU), W 10m Air Rifle
SILVER
Will Claye (OU), M Triple Jump
BRONZE
Emma Coburn (CU),W 3000M Steeplechase
Jenny Simpson (CU), W 1500M
Alex Naddour (OU), M Pommel Horse