The accident happened on Lake Langhofer.
Major Lafayette Woods with the Jefferson County Sheriff's Department tells KARK the call came in just before noon Saturday. According to Woods, a boat being driven by Richard Holland collided with a raft with the two children. The raft was being pulled by the children's grandfather, Jimmy Brown.
The girls are aged 9 and 10.
Holland told deputies he had turned around in the boat to tell his children to sit down. He then hit something he thought was a wave. When he looked again he noticed the two children floating in the water.
Woods says Holland turned around to assist in recovering the girls. Once back in the boat their grandmother performed CPR on them, reviving them both.
The girls were taken to Jefferson Regional Medical Center. One of the girl's injuries was so severe she was flown to Arkansas Children's Hospital. She's listed in critical condition.
Major Woods says deputies don't believe alcohol was involved in the accident and no charges have been filed.
The Arkansas Game & Fish Commission is conducting the investigation.