Dispatchers with Washington County Fire and Rescue say it happened just after 9:30 p.m. at mile marker 6.
A helicopter flew a two-year old to Children's Hospital as a precautionary measure, and an ambulance transported two other people. Dispatchers did not say the condition of their injuries. However, one of the passengers has been identified as 29-year old, Paige DeHart.
Dispatchers say one person was ejected, and this accident involved one car.
All lanes of I-81 reopened around 10 p.m.
Copyright 2017 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.