Maybe Pike's Peak Is In The Way

I've been perusing the maps of my spots and over the last year or so, since I have been paying any attention to it, anyway, there is a definite lack of spots from here in the northerly direction. There could be a couple of different explanations for that, however. It is entirely possible that there are no other WSPR transmitters or receivers in the area over North and South Dakota and the empty spaces in that part of Canada. It could also be that I have a flat enough angle of departure from here at 8,064 feet above sea level that the signals are successfully radiated in most every direction except for those that cross Pike's Peak, which is due north of the ranch about 40 miles distant. That would, however, not explain the success of signals to the west from here, because they are also required to cross terrain in excess of 14,000 feet above sea level within only 15 miles of the ranch. I tend to stick with the possibility that there are no stations in that wide northerly stretch of territory where the map is blank. I also don't tend to see any other spots from any other stations in that vicinity, either. Maybe North Dakota and Manitoba need some WSPR stations. Any thoughts on that phenomenon? Every antenna I test seems to display the same propagation over that area.