The purpose of this supplement is to add approximately 16,900 acres of lands on the Willamette and Deschutes National Forests to the area being considered for geothermal leasing in the Belknap-Foley Draft Environmental Statement (DES). Geothermal lease applications have been filed for the additional lands by Southland Royalty Company, Fort Worth, Texas. The same format as that used for the parent Belknap-Foley DES is followed, except that those sections, maps, tables, and appendices needing no modification were omitted from the Supplement. An exception to this general rule is the Alternatives descriptions. Included in the descriptions are all prescriptions listed in the parent document and errata pages plus additions needed to cover the supplement area. To facilitate comparison of the Alternatives, a resume (Table IIA) has also been included. Maps, tables, and appendices are given the same numbers and letters as their counterparts in the Belknap-Foley DES. Comments regarding this Supplement and the parent Belknap-Foley DES should be sent to the Forest Supervisor, Willamette National Forest by January 7, 1980.