Mother: Cassie Carpenter (adoptive), Beth Garvey (biological)
Father: Andrew Carpenter (adoptive)
Siblings: William Carpenter (adoptive; deceased)
Grandmother: Dorian Lord (adoptive)
Grandfather: Sloan Carpenter (adoptive), David Renaldi (adoptive)
Uncle: William Carpenter (adoptive; deceased)
Significant Romantic Relationships: Adriana Colon

River was born to teenager Beth Garvey, who left her infant in the manger of St. James church. Cassie Carpenter came upon the baby and brought him home. She and husband Andrew planned on adopting the boy, who they named River, until Beth returned to claim her baby. Beth took her son but soon succumbed to an illness, leaving River in Cassie and Andrew's care. The couple formally adopted the boy.

River's parents divorced in 1997 and his mother was committed to a mental institution in 1999. She was released a few years later and settled in Savannah, where River lived with her. In the summer of 2003 he came to stay with his father in Llanview, but clashes with Andrew led him to move in with his grandmother, Dorian. River met and fell in love with young Adriana Colon, but Carlotta Vega (Adriana's godmother) disapproved of the union. She did everything to keep the two apart, even sending Adriana out of town under mysterious circumstances. River tracked Adriana to Puerto Rico and snuck her back into Llanview. Upon returning, River and Adriana were shocked when Dorian claimed that Adriana was her biological daughter and thus entitled to a $30 million inheritance from Dorian's Aunt Betsy! Regardless, the two remain enamored of each other, very much in the throes of first love.