In 1949 and 1950, Donna based teams played exclusively as members of the Rio Grande Valley League.
The Donna Cardinals became members of the Class D level Rio Grande Valley League.
The Brownsville Charros, Corpus Christi Aces, Del Rio Cowboys, Laredo Apaches and McAllen Giants teams joined Donna in beginning league play.
Donna/Robstown finished behind Corpus Christi (89–51), the Laredo Apaches (80–60), Brownsville Charros (75–65), McAllen Giants (70–68) and Del Rio Cowboys (58–80) in the final standings.
[10] Both Donna based minor league teams played home games at Avila Park.