**Exhibit      12A**

**UniSource      Energy      CorporationComputation of Ratio of Earnings to Fixed      Charges**

|                                                                    |   | 3                  MonthsEnded |   |   | 12                  MonthsEnded |   | 12                  Months Ended (2) |
|-------------------------------------------------------------------------|--------|--------------------------------|--------|--------|---------------------------------|--------|--------------------------------------|
|                                                                    |   | Mar.                  31       |   |   | Mar.                  31        |   |                                 | Dec.                  31, |   |   | Dec.                  31, |   |   | Dec.                  31, |   |   | Dec.                  31, |   |   | Dec.                  31, |   |
|                                                                    |   | 2007                           |   |   | 2007                            |   |                                 | 2006 |   |   | 2005 |   |   | 2004 |   |   | 2003 |   |   | 2002 |   |
|                                                                    |   |                           |   |   |                            |   |                                 | -                  Thousands                  of Dollars - |   |
| **Fixed                  Charges:**                                     |   |                           |   |   |                            |   |                                 |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Interest                  on                  Long-Term Debt            | $      | 17,989                         |   | $      | 74,343                          |   | $                                    | 75,039 |   | $ | 76,762 |   | $ | 80,968 |   | $ | 80,844 |   | $ | 65,620 |   |
| Other                  Interest (1)                                     |   | 1,761                          |   |   | 8,377                           |   |                                 | 7,922 |   |   | 3,153 |   |   | 1,947 |   |   | 3,709 |   |   | 2,123 |   |
| Interest                  on                  Capital Lease Obligations |   | 16,152                         |   |   | 70,191                          |   |                                 | 72,586 |   |   | 79,098 |   |   | 85,912 |   |   | 84,080 |   |   | 87,801 |   |
| **Total                  Fixed Charges**                                |   | 35,902                         |   |   | 152,911                         |   |                                 | 155,547 |   |   | 159,013 |   |   | 168,827 |   |   | 168,633 |   |   | 155,544 |   |
|                                                                    |   |                           |   |   |                            |   |                                 |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| **Net                  Income**                                         |   | 4,943                          |   |   | 55,569                          |   |                                 | 67,447 |   |   | 46,144 |   |   | 45,919 |   |   | 113,941 |   |   | 34,928 |   |
|                                                                    |   |                           |   |   |                            |   |                                 |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| **Less:**                                                               |   |                           |   |   |                            |   |                                 |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Discontinued                  Operations - Net of Tax                   |   | -                              |   |   | 873                             |   |                                 | (1,796 | ) |   | (5,483 | ) |   | (5,063 | ) |   | (7,472 | ) |   | (12,919 | ) |
| Accounting                  Change - Net of Tax                         |   | -                              |   |   | -                               |   |                                 | - |   |   | (626 | ) |   | - |   |   | 67,471 |   |   | - |   |
| **Net                  Income from Continuing Operations**              |   | 4,943                          |   |   | 54,696                          |   |                                 | 69,243 |   |   | 52,253 |   |   | 50,982 |   |   | 53,942 |   |   | 47,847 |   |
|                                                                    |   |                           |   |   |                            |   |                                 |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| **Add                  (Deduct):**                                      |   |                           |   |   |                            |   |                                 |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| (Income)                  Losses from Equity Investees                  |   | (16                            | )      |   | (231                            | )      |                                 | (210 | ) |   | (2,113 | ) |   | (7,121 | ) |   | 3,051 |   |   | 3,047 |   |
| Income                  Taxes                                           |   | 3,871                          |   |   | 34,105                          |   |                                 | 43,936 |   |   | 37,623 |   |   | 37,186 |   |   | 16,531 |   |   | 26,432 |   |
| Total                  Fixed                  Charges                   |   | 35,902                         |   |   | 152,911                         |   |                                 | 155,547 |   |   | 159,013 |   |   | 168,827 |   |   | 168,633 |   |   | 155,544 |   |
|                                                                    |   |                           |   |   |                            |   |                                 |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| **Total                  Earnings before Taxesand Fixed Charges**       | $      | 44,700                         |   | $      | 241,481                         |   | $                                    | 268,516 |   | $ | 246,776 |   | $ | 249,874 |   | $ | 242,157 |   | $ | 232,870 |   |
|                                                                    |   |                           |   |   |                            |   |                                 |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| **Ratio                  of Earnings to Fixed Charges**                 |   | 1.245                          |   |   | 1.579                           |   |                                 | 1.726 |   |   | 1.552 |   |   | 1.480 |   |   | 1.436 |   |   | 1.497 |   |