The California High-Speed Rail Authority (Authority), as the Lead Agency for the California Environmental Quality Act (CEQA) for the proposed California High-Speed Rail (HSR) system, is issuing this Notice of Preparation (NOP) of a Project-Level Supplemental Environmental Impact Report (SEIR) for the Gilroy to Central Valley Wye Project Segment (G-Y Project Segment), which is part of the San Jose to Merced Project Section of the HSR system, to initiate the CEQA process and preparation of the SEIR.