The output of Hillier's scientific and artistic efforts appear to have been widely distributed, and this collection represents only a small portion. He made a significant contribution of both specimens and illustrations to the British Muesum of Natural History.

Some of his work is to be found in the following South Australian Museum archives collections:
AA 266 JG Breuther,
AA 309 EC Stirling,
AA 356 ER Waite,
SAMA 970 RC Fiveash

See also "Naming the dead Heart: Hillier's map and Reuther's Gazetteer of 2,468 placenames in North-easern South Australia" Jones, 2009