Queensland State Archives posted a photo:
From the Queensland Heritage Register.
The site has been associated with the police and judiciary in Mackay since the 1860s. Although buildings were erected and removed during the 19th and 20th centuries as the site developed, the major buildings remain and include the police station, built as a court house in 1886, the current court house, built in 1938, and two brick police residences from 1936-7. A 1960s watch house and keeper’s residence are also on this site.
The town of Mackay is named for John Mackay who entered the valley of the Pioneer River in 1860 and established a pastoral run there in the following year. In 1862 a settlement was begun on the south bank of the river and by 1863, the township had been surveyed and the first lots of land sold. It was gazetted as a port of entry and a customs house