Strange and bright strobe like lights

I have seen this bright, flickering light off and on.  This seems to occur several hours after sunset, and occurs at random times.  When the object appears – I have seen it positioned slightly off center from being directly overhead Old Leesburg Road, which leads to the high ridge road. This area is known by most as the western side of the city of Salmon, Idaho.   
This bright object seems to be brightest around or between the time of night between 7:51 pm (Mountain Time Zone) and it seems to move in erratic positioning, usually darting back and forth in a left to right movement pattern.  It has been seen to also move in an upwards and downwards movement as well.  
The night of March 9, 2015 – I was standing outside and noticed the object in a completely different spot from previous sightings.  
Tonight, I mentioned it to a friend and he also came outside and almost immediately noticed that the object was indeed moving.  If you are careful to locate the shadow from the tops of the mountains, it can clearly be seen as being a good distance from the tops of the mountains.  
As we were watching the object, it definitely seems to emit an almost strobe light effect.  
This sighting that was witnessed tonight lasted approximately 20 to 26 minutes.  Then the object seems to vanish very quickly and is not seen for several weeks approximately, and then is back in just about the same general area.