"have not been to martin falls or beyond but I have been to Thompson Manitoba and flown accross northern ontario and manitoba many times. When in the air it seems there is more water than land."
A very good point, SN. When you fly from Winnipeg-Thompson, it seems the water takes up 80-90% of the ground cover.
I was intimately involved in the construction of the highway north to Thompson in the early 60's, and there was no real problem that I recall. There were some extra miles put on because of following the high points, but there was always sufficient compactable material available. I don't recall a haulage of more than a mile or so from borrow pits on ridges into the valleys, and there were always gravel ridges within decent range. With a gravel pit, you don't want one any more than every 20 miles or so, as there has to be proper crushing facilities on site to crush and stockpile decent quantities.
The ground around ROF looks to be of a similar nature, from what pictures have been available.
Regards
K