It is impossible to avoid a complex structure here, but several tools try to ease the overall navigation. Quite rich in visual, textual and multimedia options, this site has also an advanced search in each section of the archive.
Multiple search in each branch of the NARA's archive plus possibility to search also by resource type (National Archives Internet Site; Full text of all web pages on Presidential Library web sites; selected federal agency records)
All online retrievable records can be downloaded in their original formats (audio, video, image or text versions)
A-Z linkable site index plus a site navigation guide is available, along with such useful options as "Online database tools" or "New to archival research?"
A complex interface design highlights several clear categories, yet with limited perception of the overall website structure. Maybe a better sitemap and frame organization could help the overall navigation