You are correct on several points, MD and wrong on none. The railway is the crucial point here, and for several reasons. However the main point is that it's an 'all or nothing' proposition.
If we were talking about a road it is a different scenario completely. A road can start off as an ice road first year, graduate to a winter road over the next couple of years and finally to an all season road designed for heavy traffic. During it's growth it can be utilized to provide access for the equipment required to construct the road itself as well as the mining infrastructure.
However a railroad differs in that it will have to be completed in it's entirety before it can be utilized. It will be more expensive per kilometer to build, and will likely require a road access be built alongside it to allow access for the construction process. It will require a much larger and longer study period and involvment and acceptance by many parties. Financing will also be a slow process as all parties will want to be assured their investments will provide a return of acceptable proportions.
If one intends to wait this out and realize gains because of the approach of an actual mining scenario in the ROF, they may have a long wait. Short term gains (1-3 years) will come from new discoveries and amalgamations.
Best regards
K