AT&T Mobility is proposing modifications to an existing telecommunications facility collocated on an approximately 55-foot tall (69-foot overall height with appurtenances) building located at 800 Powell Street, San Francisco City & County, CA (37 47' 32.4" N, 122 24' 32.5" W). Eocene Environmental Group (Eocene) is publishing this notice in accordance with Federal Communications Commission regulations (47 CFR § 1.1307) for Section 106 of the National Historic Preservation Act (NHPA) and for the National Environmental Policy Act (NEPA). Parties interested in commenting on this Federal undertaking or with questions on the proposed facility should contact Eocene at 8951 Windsor Parkway, Johnston, Iowa 50131. Please reference AT&T Mobility site number W 097/NF. Comments must be received within 30-days of the date of this notice.