DA40 Diamond Star
Air Traffic Control Fully Certified
Communication Breakdown; Confusion; Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Provided Assistance
Human Factors; Procedure
Aircraft X was cleared via V4 BYI direct TWF. We descended aircraft to 100 and shipped as per LOA. TWF called and asked if the aircraft was over DRYAD or MALTT or something for the ILS. We said no; that they were on V4 to BYI. They said okay and asked for control. We gave them control. Later; we saw the aircraft was westbound into high MEA. We called and asked what they were doing and thought the controller said they were going to DRYAD and we informed them they were entering high MEA. They asked what altitude they needed and we said 120 (the MEA was 113). They gave us some explanation of what their strip showed (direct MEDEA or something). We again said they were on V4 and our strip showed that. The controller climbed to 120 and gave direct DRYAD. The plane did enter the 113 MEA when they were at 100.It seemed like the TWF Controller didn't have the complete flight plan on their strip. I don't know why that is and what the controller gave the aircraft or was thinking. They should have had the routing.
Salt Lake Center Controller reported an aircraft was allowed to operate below the Minimum En-route Altitude.