I see no advantage converting color to B/W. The advantage of b/w was when the film was orthopanamanthic (si)which had great laditude to catch all the shades of black, gray, grit, or what ever in the shadows. With the high contrast with any color film, and the high altitude in your area, none of the film or digital cameras can catch the details in the shadows. Never use the 1A filter above 8,000'
You want a system that can catch all the details in very low light shadows and not be washed out in the very brightly sun lit areas.
Your original color views have a all black engines, which you attempt to convert to sepia or b/w but will not be corrected without a lot of "photo shop" time.