EXHIBIT 16

[PRICEWATERHOUSECOOPERS LLP LETTERHEAD]






March 18, 2005

Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, D.C. 20549

Commissioners:

We have read the statements made by the Minnesota Power and Affiliated Companies
Retirement Savings and Stock Ownership Plan (copy attached), which we understand
will be filed with the Securities and Exchange Commission, pursuant to Item 4.01
of Form 8-K, as part of the Retirement  Savings and Stock Ownership  Plan's Form
8-K report dated March 15, 2005.  We agree with the  statements  concerning  our
Firm in such Form 8-K.

Very truly yours,

/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP