What was found
One half hour into the flight from GSP to ORD, the crew noted a hydraulic high temperature caution. Hydraulic temperature reached 200 degrees C. The crew followed the QRH procedures shutting down the L/H engine and returned to GSP where the aircraft landed without incident. Maintenance personnel removed and replaced the #1 hydraulic system reservoir. Operational and leak checks were satisfactory and the aircraft was returned to service.