Series 4 consists of correspondence written by or addressed to Kim Stafford, and includes handwritten and typed letters, postcards, greeting cards, and after 2000 printed copies of selected email messages saved for their substantial content. (The collection thus spans the transition into the digital age.) Items are generally arranged chronologically by date (including several separate chronological sequences from early to late), with the exception of "clusters," or groupings of correspondence compiled by Kim Stafford that are thematically centered around an individual or topic. Individual correspondents represented in these different clusters can often be found by searching by their names.

In this series Kim Stafford has been abbreviated to "KS" in item descriptions.