Air carrier First Officer reported traffic was climbing towards the aircraft from the opposite direction of the runway. The flight crew received a TCAS RA alert and the pilot from the other aircraft never made any nor responded to any calls.

Narrative

We had just turned onto final to Runway 23 over the final approach fix and had started our final descent to land. We were fully configured and at our final approach speed. We had previously briefed GA traffic as a threat and has been monitoring CTAF and making appropriate calls. The Captain then noticed a TCAS target moving straight at us and climbing towards us off of the opposite direction runway. He said be ready for a TCAS. I arrested our descent; looked up; and immediately made visual contact with the other airplane. Almost immediately after; the TCAS RA gave a descend command. I pitched down to a roughly 1700 FPM descent and watched the intruding pass directly overhead roughly 400 ft. above us. We kept descending until we heard clear of conflict."At that point I steadied our descent. We were above 1000 ft. and on speed and on glidepath so we continued the approach and landed normally. The pilot of the other aircraft did not make any CTAF calls or respond to us when we broadcasted that they had caused an RA. The primary contributing factor of this incident was the pilot of the other airplane not making any radio calls while departing an uncontrolled airport. Additionally; BFF Runway 12/30 is closed; leaving 5/23 as the primary runway. At the time of the incident; the wind was 190/3 so while technically favoring 23; any runway would be acceptable. There are no taxiways to the departure end of 23; so landing 23 and departing 5 is the only way to avoid backtaxiing. We did not realize how strongly the airport layout encouraged departure off of Runway 5; and since the wind was slightly favoring 23 we were not expecting opposite direction departures. A warning in the company charts would help to draw attention to this fact and help with crews' situational awareness when landing on Runway 23."