The 121-hectare (300-acre) protected area was established with the focus on conservation of the native flora and fauna, and preservation of the geological features in the Jacksons Creek, a part of the Maribyrnong valley, north-west of Melbourne.

Over the last one to two million years, the slow cutting by Jackson Creek of its valley down into the basaltic plains and through the underlying trap rock exposed these geological structures.

[5][6][7] A Friends' group, (the first in Australia) the "Friends of Organ Pipes" (FOOPS), comprising conservation activists to support the efforts of rehabilitation of the OPNP's indigenous flora and fauna, supplemented the work of the Victoria Park system under which the OPNP was declared a National Park.

[1] The national park, designated to cover an area of 121 hectares (300 acres), is situated 20 kilometres (12 mi) to the northwest of Melbourne city.

According to records maintained at Melbourne Airport since 1972, the average annual rainfall in the park area is 580 millimetres (23 in)[8] (occurs during winter and spring).

[3] The earliest settlers in the plains of the park area and its vicinity were the Australian Aboriginal Woiworung people of the Kulin nation in the Yarra and Maribyrnong River valleys.

[6][7] They introduced new variety of plants such as boxthorn hedges for fences and trees such as oaks, willows and pine, creating an ambiance of their homeland.

[3][7] During this period, there was a hamlet near the Organ Pipes and a suspension bridge across Jacksons Creek to reach a school and farm lands that surrounded the village.

The stables in the park area were built by the Halls in which the Hayes family lived, and a Jackson Bay fig tree is located near the Information Center.

[7] An area of 20 hectares (49 acres) of land was added under the National Parks (Amendment) Act 1978 (Vic.)

[1] The particular site was chosen because of the presence of several interesting geological features, including the "Organ Pipes", themselves a pattern of vertical pipe-like rock structures exposed by the erosion of the creek, and a tessellated pavement, where the rock surface has been split into regular "tiles" by joints related to columnar jointing.

[9] These landforms were created by the incision of the Jacksons Creek into thick lava flows that erupted about 2.5 to 2.8 million years ago during the Pleistocene Period.

[3] Sedimentary rock and fossils found in the park are also dated back 400 million years, an indication that the area was once a sea.

About 2.5 to 2.8 million years ago giant lava flows known as a flood basalt spread across the land from surrounding volcanoes.

The geological features in the Park, all of volcanic origin, have been categorized under the broad heads namely, the Organ Pipes, Tessellated Pavement, Rosette Rock, Scoria cone and the Sandstone layer.

The cooling effect caused shrinkage and as scientifically elaborated: As seen now, the rock formation rises to a height of 20 metres (66 ft) and is considered as the best example of columnar jointing in Victoria.

[3] The unusual shape of Jackson Creek Organ Pipes is attributed to the columnar structure which is rare and occurred at strategic location where the down cutting action of the stream created the post-volcanic valley.

They are stated to be part of a deep lead—an ancient stream bed buried by a lava flow, and later revealed by the downcutting of Jackson Creek.

[3] The volcanic soils in the park formed above basaltic rock base are found in the valleys and have gentle or flat slopes.

Work continued to remove introduced plants and vermin, and reintroduce natural vegetation and wildlife to the park.

[3] Six types of vegetation witnessed, consequent to the re-vegetation programme launched by the Park Administration with assistance from FOOPS, are in three landform zones reflecting the soils derived from the underlying geology.

[3] On the banks of the valley formed by Jacksons Creek are found stray examples of remnant indigenous vegetation including river red gum riparian woodland (also manna gum and blackwood species), reed bed and sedgeland species and also shrub land and grasslands.

Organ Pipes were formed approximately a million years ago when huge quantities of molten lava were ejected from volcanoes near what is now Sunbury and flowed over the Keilor Plains.

[3] The park is also a popular tourist destination as it houses the Organ Pipes, The Tessellated Pavement, the Rosette Rock and much more.

There is a Visitors Center and picnic area next to the car park and short walking tracks down a rather steep hill to Jacksons Creek and the rock features.

The birds and other animals seem to be unaffected by this and an early morning or dusk visit will be rewarded by sightings of swamp wallabies and eastern grey kangaroos.