Air Traffic Control Developmental
Distraction; Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued New Clearance
Human Factors; Procedure
Aircraft was being vectored for an RNAV approach to Runway 17 from the east; after looking up the approach plate and seeing that the crossing altitude at the IAF HOXID was 2000 I cleared him to cross HOXID at 2000 cleared approach.  The aircraft started his descent for the approach out of 3000. The Low altitude/conflict alert alarm went off when the aircraft was at about 2800 in a 3000 foot MVA that is only a few miles east of HOXID. I issued the low altitude warning and climbed him back to 3000.I had my MVA map off at the time of the event. When I looked up the approach plate and saw the altitude was 2000 at the IAF; I did not realize the MVA would be a factor that was east of that point. I immediately saved my preference sets to ensure that my MVA map would remain on at all times.
I90 TRACON Controller reported an aircraft experienced a CFTT near HOXID intersection.