The Status Report of U.S. Government Gold Reserve can be found on FiscalData and is available for download in multiple machine-readable formats with complete metadata.
Deep Storage is the portion of the U.S. Government-owned gold bullion reserve which the Mint secures in sealed vaults that are examined annually by the Treasury Department's Office of the Inspector General and consists primarily of gold bars.
U.S. Department of the Treasury. Fiscal Service, U.S. Mint Held Gold Deep Storage: Denver, CO [DNVCOGTA], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/DNVCOGTA, December 4, 2020.