Sodor was "discovered" in 1949, when Thomas' branch from Knapford to Ffarquhar was drawn, and the connecting line to Tidmouth.
From "The Thomas the Tank Engine Man". Used with the approval of Brian Sibley
A map of the complete island came to light around 1950:
A leaf in the Rev W Awdry's model railway scrapbook. Part of the "Awdry Study" at the Narrow Gauge Railway Museum in Tywyn, Wales. With thanks to NGRM Secretary Chris White, Trustee Winston McCanna, Attendant Ron Whitaker and all other helpful TRPS members.
By 1952 this was beautifully realised in a large relief map by PR Wickham, comissioned by Edmund Ward for the Rev. Awdry, now part of the "Awdry Study" at the NGRM, Tywyn
With many thanks to SiF member and recent NGRM patron, Clay H.
for permission to post his photo of the map here. (Aug. 2007)
PR Wickham faithfully built stock for the Rev's model railway and produced other plans and at least one map, such as this of Thomas' branch in 1959:
From Railway Modeller December 1959.
The Wickham relief map was the basis for this Edmund Ward publication of a 22" x 11½" map in 1958:
Also later reproduced for the endpapers of "Thomas the Tank Engine: The Complete Collection"
In the interim, Awdry produced this map in his typed book "Sodor History"
Part of the "Awdry Study" at the NGRM, Tywyn.