He sold at the right time, at the height of the placer boom.
When he prophesied to his old cronies, in the Moosehorn Saloon, that within five years town lots in Dawson could not be given away, while the cabins would be chopped up for firewood, he was laughed at roundly, and assured that the mother-lode would be found ere that time.

But he went ahead, when his need for lumber was finished, selling out his sawmills as well.

Likewise, he began to get rid of his scattered holdings on the various creeks, and without thanks to any one he finished his conduit, built his dredges, imported his machinery, and made the gold of Ophir immediately accessible.

And he, who five years before had crossed over the divide from Indian River and threaded the silent wilderness, his dogs packing Indian fashion, himself living Indian fashion on straight moose meat, now heard the hoarse whistles calling his hundreds of laborers to work, and watched them toil under the white glare of the arc-lamps.
But having done the thing, he was ready to depart.

And when he let the word go out, the Guggenhammers vied with the English concerns and with a new French company in bidding for Ophir and all its plant.