Medium Transport
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 2
Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued New Clearance
Airspace Structure; Human Factors
I was working sector 12R. Frequency congestion was high; traffic volume and complexity were rated between 3 and 4. Aircraft X wanted a visual approach in to TEX. I descended the aircraft to 120 (lowest possible MIA in vicinity). I asked the aircraft if he had the airport in sight (quickly coming to 160 MIA). He said negative. I waited several more minutes and I asked again; he said negative and they were in and out of cloud bases at the time and he would advise me in several more miles. Overhead of Aircraft X I had an inbound Aircraft Y to MTJ airport on an approach. I had to climb Aircraft X to miss the terrain; but had to stop Aircraft Y. I stopped Aircraft Y approach clearance and turned him 30L for Aircraft X. I advised Aircraft X due to terrain I would need to climb him; and climbed him to 160. I failed to climb Aircraft X before he reached the 160 MIA; entering the MIA at 128 in a climb to 160.Change my personal technique of using visual approaches in to TEX airport so that the aircraft is either cleared for an IAP or will depart the ETL VOR on a heading to avoid terrain.
ZDV Center Controller reported an altitude violation when an aircraft under ATC Control entered an area below the Minimum IFR Altitude.