Blue Earth Lake is located in a provincial park in the southern interior of British Columbia, Canada. You climb high into the hills above the desert and find this gem of a lake and (almost) no people.
There is a story. The road gets much much, worse. Do not believe the maps of the area. If you keep going, soon there is no road, and nowhere to turn around. You will need to drive through creeks, bottom out in mud holes, and chop down trees that block the way. Eventually (if you make it through), you will find yourself on a ranch, with a heavy chain preventing the possibility of exiting to the road.
As going back the way you came is not an option, here is a hint. Combination = 4000.