The collection primarily consists of postmarked envelopes, postcards, and correspondence that Bilyeu organized in albums. The albums included postmarked envelopes from all 36 Oregon counties as well as Portland, Oregon; postcards, stationery, and other material relating to the 1905 Lewis and Clark Centennial Exposition in Portland; and to railroad lines. The collection also includes books, catalogs, scholarly articles, and other loose materials that Bilyeu possessed.

The collection primarily consists of postmarked envelopes, postcards, and correspondence that Bilyeu organized in albums. The albums included postmarked envelopes from all 36 Oregon counties as well as Portland, Oregon; postcards, stationery, and other material relating to the 1905 Lewis and Clark Centennial Exposition in Portland; and to railroad lines. The collection also includes books, catalogs, scholarly articles, and other loose materials that Bilyeu possessed.