The Mount Lofty Ranges stretch from the southernmost point of the Fleurieu Peninsula at Cape Jervis northwards for over 300 kilometres (190 mi) before petering out north of Peterborough.

The mountains have a Mediterranean climate with moderate rainfall brought by south-westerly winds, hot summers and cool winters.

The ranges encompass a wide variety of land usage, including significant residential development, particularly concentrated in the foothills, suburbs of Stirling and Bridgewater, and the towns Mount Barker and Victor Harbor in particular.

An iron sulfide mine at Brukunga, northeast of Mount Barker, operated from 1955 to 1972, proving a valuable source for the production of superphosphate fertilisers vital for the postwar development of the State's outlying agricultural areas.

The ranges form part of the water supply for Adelaide, and there is an extensive infrastructure of reservoirs, weirs, and pipelines, on the Torrens, Onkaparinga, Little Para and Gawler River catchments.

The northern end of the ranges are home to two curiosities: a tiny township by the name of Yongala, familiar to South Australians for commonly being the coldest place in the state (being a hundred kilometres inland, and on a somewhat elevated plateau as with much of the Mid North).

The southern ranges and slopes of Mount Lofty overlooking the Adelaide Plains have been block-faulted to form a half-graben structure.

Larger quakes in the southern ranges are fairly rare: the last to hit a major centre was the 1954 Adelaide earthquake that occurred on 1 March.

A significant aspect of the geology of the Adelaide area is a number of Tertiary marine sands deposits, many of which have been extensively quarried.

Similar habitats can be found on the offshore Kangaroo Island which is included by the World Wildlife Fund in the Mount Lofty woodlands ecoregion.

[4] The mountains are home to a number of marsupials such as the koala, western gray kangaroo, southern brown bandicoot along with the egg laying echidna.

[5] The hillsides have largely been cleared of woodland for fruit growing and other agriculture and the urban growth of Adelaide particularly on the lower slopes, leading to loss of habitat and local extinction of wildlife species including all species of bettong and quoll marsupials and birds including regent honeyeater (Xanthomyza phrygia), swift parrot (Lathamus discolor), king quail (Coturnix chinensis), brown quail (C. ypsilophora), and azure kingfisher (Alcedo azurea).