There are several such "lists."
The one that is maintained by the company is called the shareholder registry. That is a list that the company has given to it by the brokerage firms. It is a start, but not a full list, because many individual shareholders hold their stock with say Merrill Lynch, in "street name" or anonymously.
A more useful list is the one of institutional ownership maintained by the SEC. Basically, "large" holders (of more than 5 percent of the stock) have to register their holdings with the SEC. More to the point, large holders of stocks, the Vanguards, Fidelitys, etc. over a certain size, have to file ALL their holdings of stock with the SEC. These are the people you want to contact if you want to start a proxy fight.
The most comprehensive list is held by the Depositary Trust Company. People try to get that list only in rare instances.