This environmental impact statement (EIS) assesses the direct and indirect environmental consequences of federal approval of conversion of existing oil and gas leases within the Sunnyside Special Tar Sand Area (STSA) to combined hydrocarbon leases. These lease conversions are proposed by five applicants. Each applicant has submitted a plan of operations for converting these leases. This EIS addresses the collective and cumulative impacts of the proposed actions, a partial conversion alternative and/or special mitigation, a unitized development alternative, and a no action alternative. Major project components include four proposed open pit mines, one in-situ area and four processing plants.