Exhibit 12



GAS TRANSMISSION NORTHWEST CORPORATION

EXHIBIT 12 - RATIO OF EARNINGS TO
FIXED CHARGES



|                                         |  |                       |      |     |      |   |       |  |      |       |      |   |       |  |   |      
|---------------------------------------- |  | --------------------- | ---- | --- | ---- | - | ----- |  | ---- | ----- | ---- | - | ----- |  | - | -----
|                                         |  | 2004                  |      |     | 2003 |   | 2002  |  | 2001 |       | 2000
|                                         |  | (Dollars in Millions)
|Earnings                                 |  |                       |      |     |      |   |       |  |      |       |      |   |       |  |   |      
|Income (loss) from Continuing Operations |  | $                     | (7.4 | )   |      | $ | 53.9  |  | $    | 79.0  |      | $ | 76.4  |  | $ | 58.4 
|Adjustments:                             |  |                       |      |     |      |   |       |  |      |       |      |   |       |  |   |      
|Income taxes                             |  |                       | 6.8  |     |      |   | 34.9  |  |      | 43.7  |      |   | 34.5  |  |   | 37.4 
|Fixed charges (as below)                 |  |                       | 39.0 |     |      |   | 39.9  |  |      | 38.9  |      |   | 38.0  |  |   | 40.9 
|                                         |  |                       |      |     |      |   |       |  |      |       |      |   |       |  |   |      
|Total adjusted earnings                  |  | $                     | 38.4 |     |      | $ | 128.7 |  | $    | 161.6 |      | $ | 148.9 |  | $ | 136.7
|                                         |  |                       |      |     |      |   |       |  |      |       |      |   |       |  |   |      
|Fixed charges:                           |  |                       |      |     |      |   |       |  |      |       |      |   |       |  |   |      
|Net interest expense                     |  | $                     | 38.2 |     |      | $ | 39.2  |  | $    | 35.2  |      | $ | 37.0  |  | $ | 40.4 
|Adjustments:                             |  |                       |      |     |      |   |       |  |      |       |      |   |       |  |   |      
|Interest component of rents              |  |                       | 0.3  |     |      |   | 0.3   |  |      | 0.4   |      |   | 0.3   |  |   | 0.1  
|AFUDC debt                               |  |                       | 0.5  |     |      |   | 0.4   |  |      | 3.3   |      |   | 0.7   |  |   | 0.4  
|                                         |  |                       |      |     |      |   |       |  |      |       |      |   |       |  |   |      
|Total fixed charges                      |  | $                     | 39.0 |     |      | $ | 39.9  |  | $    | 38.9  |      | $ | 38.0  |  | $ | 40.9 
|                                         |  |                       |      |     |      |   |       |  |      |       |      |   |       |  |   |      
|Ratio of earnings to fixed charges       |  |                       | 1.0  | (a) |      |   | 3.2   |  |      | 4.2   |      |   | 3.9   |  |   | 3.3  
|                                         |  |                       |      |     |      |   |       |  |      |       |      |   |       |  |   |      
|Amount of deficiency                     |  | $                     | 0.7  |     |      |   |       |  |      |       |      |   |       |  |   |      

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|(a) |  | Removing the impact of the charge to other income and (income deductions) for the Liberty Matter of $95.4 million and the $30.0 million tax effect thereof, net income would have
been $58.0 million and the resulting ratio of earnings to fixed charges would have shown as 3.4.
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