EXHIBIT 99.1 GEODYNE ENERGY INCOME PROGRAMS 2000 YEAR-END ESTIMATED VALUATION ON A PER UNIT BASIS(1) CASH DISTRIBUTIONS PER UNIT 2000 YEAR 1999 ------------------------------------ END PER UNIT YEAR-END CUMULATIVE FORMATION UNIT ESTIMATED ESTIMATED 2000 DISTRIBUTIONS P/SHIP DATE SIZE VALUATION(2) VALUATION(2) TOTAL THRU 12/31/00 P/SHIP - ------ --------- ---- ------------ ------------ ----- -------------- ------ III-A 11/21/89 $100 $64.35 $23.41 $6.42 $105.60 III-A III-B 01/24/90 $100 $60.01 $23.84 $7.33 $116.59 III-B III-C 02/27/90 $100 $73.36 $27.64 $8.44 $83.85 III-C III-D 09/05/90 $100 $91.64 $39.93 $13.22 $84.21 III-D III-E 12/26/90 $100 $96.11 $50.34 $15.73 $90.60 III-E III-F 03/08/91 $100 $79.72 $31.58 $9.59 $62.07 III-F III-G 09/20/91 $100 $82.18 $35.59 $10.93 $61.38 III-G (1) This chart must be read in connection with the letter dated January 26, 2001, providing important assumptions and other information on the methodology used to calculate these estimates. (2) 2000 Year-End estimates use $27.52 per barrel of oil and $6.03 per thousand cubic feet ("MCF") of gas compared to $22.75 per barrel and $2.24 per MCF of gas for the 1999 Year-End estimates.