William L. Rhein (1910-1999) was a dentist and amateur naturalist who made the only known photographic documentation of an Imperial Woodpecker
(Campephilus imperialis) in the form of a 16-mm film taken in Durango state, Mexico, in 1956. During three expeditions to the Sierra Madre Occidental in the
1950s Rhein also observed Mexican Wolf (Canus lupus baileyi), now extinct in the wild, as well as Thick-billed Parrot (Rhynchopsitta pachyrhyncha) and
Sierra Madre Sparrow (Xenospiza baileyi), now both rare and endangered species. After his Mexican work, Rhein reported observing a female
Ivory-billed Woodpecker (Campephilus principalis) in the Florida panhandle in 1959, approximately one mile east of the Aucilla River (Rhein letter
to J.T . Tanner, 1 March 1962, held in the Cornell Division of Rare and Manuscript Collections, collection no. 2665). This is considered one of the more
credible post-1944 sightings of that species in the U.S. (Jackson 2002). In the 1960s Rhein extensively filmed nesting Common Raven
(Corvus corax) in Pennsylvania, then a rare species in the state. In the 1980s and 1990s Rhein was a champion Rhododendron horticulturist.

The photo shows William L. Rhein at his residence, Mechanicsburg, PA, USA