Dear Mr. Graham,
Thank you for posting your request on History Hub!
The Truk Atoll (now called Chuuk Lagoon) was used as the main base of the Imperial Japanese Navy in the South Pacific since taking possession of the islands after World War I. We searched the National Archives Catalog and located 1 series, 60 file units & 1 item in the Records of the Office of the Chief of Naval Operations (Record Group 38) that relate to the Truk Atoll during World War II and include aerial reconnaissance, war diaries, and after-action reports from the World War II War Diaries, Other Operational Records and Histories, ca. 1/1/1942 - ca. 6/1/1946 Records Series. These digitized records may be viewed using the Catalog. For access to non-digitized records, please contact the National Archives at College Park - Textual Reference (RDT2) at firstname.lastname@example.org.
Some of the remaining World War II-era structures in the Truk Atoll are listed on the National Register of Historic Places (NRHP). One NRHP submission is for the Japanese Army Headquarters.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDT2. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this is helpful. Best of luck with your research!