Regardless of one's politics, the current administration in Washington and Juneau are the most likely to railroad through a mine with such potential. The governor is currently debating with our (I live here) legislature about budget line item vetos and blah blah blah. Once everyone in Juneau has a budget they can live with and it isn't on the table anymore, I believe the governor is going to make the contentious pebble mine a priority for many reasons (jobs that last more than 6 months, goods and services from hub communities and Anchorage, tax revenue, etc.).
In short, I believe serious progress toward moving dirt will happen this year; in the past, belief that they were close to digging got the price to over $20. We're really close to the all-time lows compared to the all time highs so even if one went long right now at $0.50 it's still a great entry.
I can only imagine what the price will reach when they actually get moving dirt but I would imagine it would be north of $21.00. Considering stock prices for other companies with similarly gargantuan mines; it wouldn't be too crazy to hope for $50.