- To reach people through our prayers, our presence, our gifts and our service. Three Rivers First United Methodist Church Post Office Box 417 Three Rivers, Texas 78071 361-786-3217 Three Rivers is a South Texas community located half way between San Antonio and Corpus Christi. Please join us at our church on the corner of Church Street and Caves Avenue, one block east of Hwy. 281. The space for ...www.gbgm-umc.org/trfumc