Morley Nelson Snake River Birds of Prey National Conservation Area Boundary Modification Act of 2017 This bill modifies the boundary of the Morley Nelson Snake River Birds of Prey National Conservation Area in Idaho to: (1) include specified Bureau of Land Management (BLM) administered land and certain Bureau of Reclamation administered land, and (2) exclude specified lands identified as the Segment 8 Revised Proposed Route and as the Segment 9 Revised Proposed Route. The Department of the Interior shall issue to Gateway West (a high-voltage transmission line project in Idaho and Wyoming) a right-of-way for such proposed routes, which is to be used for the construction and maintenance of transmission lines and for access roads and activities related to fire prevention and suppression, subject to construction mitigation and conservation requirements. Interior shall: (1) administer the BLM and Reclamation administered lands as part of the National Landscape Conservation System, and (2) continue to administer the proposed route lands but as lands that are not included in the conservation area. The bill transfers from Reclamation to the BLM administrative jurisdiction over the Reclamation administered lands. Interior shall amend the management plan for the conservation area in order to address the long-term management of the BLM and Reclamation administered lands, including for livestock grazing, hunting, fishing, and motorized access. Specified federal land in the Cotterel Wind Power Project area may not be used for producing electricity from wind.