A TRACON controller reported they allowed an aircraft to fly below the minimum vectoring altitude.

Attributes
ACN	1744487
Time
Date	202006
Local Time Of Day	1801-2400
Place
Locale Reference	S56.TRACON
State Reference	UT
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	EMB ERJ 170/175 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 6.0
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

Narrative:

We were in a north flow. Staggered airspace configuration. Feeders were stacking final so I offered to take aircraft X from a 110 heading. Aircraft X was originally descended to 13;000 feet. I had a general aviation(GA) aircraft inbound from the south. I had assigned 13;000 feet to aircraft X and 12;000 feet to the GA aircraft and then I went back and swapped the altitudes. I didn't realize aircraft X would not miss the 12700 foot minimum vectoring altitude(MVA). The supervisor asked me about aircraft X one mile from the MVA line. I immediately turned aircraft X 15 degrees and asked pilot if he had the terrain in sight. He did. I instructed the pilot to provide their own terrain and obstruction clearance through the MVA which pilot read back. I realize this is not correct application of this rule. 15 degrees was not enough to clear the MVA. Aircraft X entered the MVA by .4 of a mile for 2.7 miles as they passed over the mountain ridge line. I should have let the feeders work out their own plan. I had been off for 10 days and this was my first session back. I could have reviewed the airspace more.

Original NASA ASRS Text

Title: A TRACON Controller reported they allowed an aircraft to fly below the Minimum Vectoring Altitude.

Narrative: We were in a north flow. Staggered airspace configuration. Feeders were stacking final so I offered to take Aircraft X from a 110 heading. Aircraft X was originally descended to 13;000 feet. I had a General Aviation(GA) aircraft inbound from the south. I had assigned 13;000 feet to Aircraft X and 12;000 feet to the GA aircraft and then I went back and swapped the altitudes. I didn't realize Aircraft X would not miss the 12700 foot Minimum Vectoring Altitude(MVA). The Supervisor asked me about Aircraft X one mile from the MVA line. I immediately turned Aircraft X 15 degrees and asked pilot if he had the terrain in sight. He did. I instructed the pilot to provide their own terrain and obstruction clearance through the MVA which pilot read back. I realize this is not correct application of this rule. 15 degrees was not enough to clear the MVA. Aircraft X entered the MVA by .4 of a mile for 2.7 miles as they passed over the mountain ridge line. I should have let the feeders work out their own plan. I had been off for 10 days and this was my first session back. I could have reviewed the airspace more.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.