Exhibit 11.1

WESTERN GAS RESOURCES, INC.
COMPUTATION OF PER SHARE EARNINGS
DECEMBER 31, 2004

|                                                    |                                                                                 | Weighted
Average
Shares Of
Common
Stock
Outstanding |            | Net
Income |             | Earnings
Per Share
Of Common
Stock
|--------------------------------------------------- | ------------------------------------------------------------------------------- | --------------------------------------------------- | ---------- | ---------- | ----------- | ----------------------------------
|Net income                                          |                                                                                 |                                                     |            | $          | 119,215,000 |                                   
|Weighted average shares of common stock outstanding |                                                                                 | 72,419,980                                          |            |            |             |                                   
|Less preferred stock dividends:                     |                                                                                 |                                                     |            |            |             |                                   
|                                                    | Special dividend on redemption of $2.625 cumulative convertible preferred stock |                                                     |            |            |             | (46,423                           
|                                                    | $2.625 cumulative convertible preferred stock                                   |                                                     |            |            |             | (788,902                          
|                                                    |                                                                                 |                                                     |            |            |             |                                   
|                                                    |                                                                                 | 72,419,980                                          |            | $          | 118,379,675 |                                   
|                                                    |                                                                                 |                                                     |            |            |             |                                   
|Basic earnings per share of common stock            |                                                                                 |                                                     |            |            |             |                                   
|                                                    |                                                                                 |                                                     |            |            |             |                                   
|Assume exercise of common stock equivalents         |                                                                                 | 1,074,767                                           |            |            |            |                                   
|                                                    | (Anti-dilutive common stock equivalents are not used in this calculation)       |                                                     | 73,494,747 |            | $           | 118,379,675                       
|                                                    |                                                                                 |                                                     |            |            |             |                                   
|Fully diluted earnings per share of common stock    |                                                                                 |                                                     |            |            |             |                                   
|                                                    |                                                                                 |                                                     |            |            |             |                                   

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