Complex sentence: The town and region was known as'Frankland River' until 1935 until the building of a post office when it is said that the postmaster shortened the name as it was considered too long to fit on signs and documents.
Split into simpler sentences: The town and region was known as'Frankland River' until 1935 when it was altered. After the building of a local post office, it is said that the postmaster shortened the name to "Frankland" as the use of Frankland River was considered too long to fit on signs and documents.