There have been a range of stories about Marcus Daly’s wealth and I think the best answers are in his will, which was filed in Deer Lodge, MT after his death with William Scallon, who succeeded him at Anaconda, being one of the witnesses.
The will left 1/3 of the estate to his wife Margaret and the balance to be split between his four children, Margaret, Mary, Marcus Haggin and Harriet. Margaret was named executor and held the whole in trust till the children reached the age of 30. The oldest was 23 at the time of his death in 1900.
The estate was initially estimated at being valued at 11.1 million dollars with about 6 million in Anaconda/Amalgamated stock. But the value of the stock and some of the properties fell and by the time fees, estate taxes and claims against the estate were paid (early 1902), the value was reduced to about 7.3 million, of which about 3.3 million was cash and the balance a variety of bonds, stocks and other financial investments.
With Margaret ending up with a little over 2.4 million, it is probable that her investment advisor, John D Ryan, made her substantially more money in entities like the Montana Power Company, than Marcus left her in Anaconda.
It is also notable, that the will cites no ownership in properties like the Missoula lumber business, coal mines, the Montana Hotel or the iron works or clay plants that supplied Anaconda. While some sources cite that Daly made millions from these enterprises, they were all a tightly managed part of the Anaconda enterprise.