EXHIBIT 12.01 MOUNTAIN FUEL SUPPLY COMPANY RATIO OF EARNINGS TO FIXED CHARGES 12 MONTHS ENDED YEAR ENDED DECEMBER 31, MARCH 31, --------------------------------------------------- --------- 1992 1993 1994 1995 1996 1997 ------- ------- ------- ------- ------- --------- (DOLLARS IN THOUSANDS) Earnings Income before income taxes................. $30,846 $32,778 $31,255 $31,374 $42,434 $48,603 Plus debt expense.......................... 15,254 15,423 15,886 16,580 16,637 16,707 Plus allowance for borrowed funds used during construction..................... 246 228 321 390 277 265 Plus interest portion of rental expense................................. 83 126 204 430 187 170 ------- ------- ------- ------- ------- --------- $46,429 $48,555 $47,666 $48,774 $59,535 $65,745 ------- ------- ------- ------- ------- --------- ------- ------- ------- ------- ------- --------- Fixed Charges Debt expense............................... $15,254 $15,423 $15,886 $16,580 $16,637 $16,707 Plus allowance for borrowed funds used during construction..................... 246 228 321 390 277 265 Plus interest portion of rental expense................................. 83 126 204 430 187 170 ------- ------- ------- ------- ------- --------- $15,583 $15,777 $16,411 $17,400 $17,101 $17,142 ------- ------- ------- ------- ------- --------- ------- ------- ------- ------- ------- --------- Ratio of Earnings to Fixed Charges(1)........ 2.98 3.08 2.90 2.80 3.48 3.84 - ------------------ (1) For the purposes of this presentation, earnings represent income before income taxes and fixed charges. Fixed charges consist of total interest charges, amortization of debt issuance costs and losses from repurchasing debt, and the interest portion of rental costs.