It is hoped that a best-case scenario could see official trail construction begin before the end of the year.

After more than seven years of planning, consultation and redesigning, the Review of Environmental Factors (REF) for the network has gone on public exhibition, with 51km of trails included from the south and west side of Mt Keira to Kembla Heights and Windy Gully on Mt Kembla.

Read more: Former judge says South32 emails risk 'unfair influence' in planning

Illawarra Mountain Bike Alliance member Gary Pesavento said this would be the "last and most important" chance for riders to "help get the project over the line".

"It's certainly been a long time coming, but the REF is really the last significant piece of the planning jigsaw puzzle that has been worked on by numerous government bodies and community groups over the past seven-plus years," he said.

He said after a long and slow process of going through multiple stages of planning, this consultation was about how the REF considered risks to the environmental and heritage values of the escarpment.

"I think the general comment from most people is just that it has taken way too long - and I guess I would agree with that," he said.

"But the flip side is that given it's a state conservation area where the bulk of the trails are going, National Parks are bound by certainly legislative processes.

"Unfortunately when you're dealing with that kind of state government bureaucracy things take time."

Networks of unofficial trails have been built over decades in the escarpment conservation area, but this project would result in legally approved riding paths with the potential to draw mountain bike enthusiasts from around Australia.

Some points remain uncertain, with land owned by Sydney Water and South32 - vital for linking up the trail network - still to receive clearance from owners to be included.

But Mr Pesavento said the water utility and the miner had been at the table throughout consultations so were part of the process.

"The hope and the expectation is that once the REF is approved, those agencies will then make a commitment to getting on board," he said.

He said a "best-case scenario" could see construction on the trails getting started this year, if the REF is approved and other factors line up.

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