Question: In which Australian state can one find a national park accessed by a major road which extends from Sydney to Port Augusta?

Context paragraphs:
Daniel Spencer (environmentalist): Daniel Spencer is a young South Australian climate activist, originally from Renmark in the state's Riverland region.  He has held prominent leadership roles in the Australian Youth Climate Coalition, the Repower Port Augusta campaign and the Walk for Solar.  His work has focused on promoting a vision and building community support for the replacement of the coal-fired power stations at Port Augusta with a concentrated solar-thermal power generation alternative.  Dan's contributions to climate activism have been widely acknowledged and awarded.  In 2012, Dan received the Bob Brown Foundation's inaugural Young Environmentalist of the Year award and was recognized by the Conservation Council of South Australia with the Jill Hudson Award for Environmental Protection.  In 2013, he received the Flinders Ports Environment Award at the Channel 9 Young Achievers Awards in South Australia.  Dan has appeared in documentary films focusing on climate change and activism, including "Revolution" and "2 Degrees" and is also a musician, songwriter and lead singer for the roots reggae band "Babylon Burning".

Wilmington–Ucolta Road: Wilmington–Ucolta Road is a 98 kilometre major road connecting Port Augusta to Peterborough and beyond to Broken Hill, in South Australia.  It forms as a connecter road between the Princes Highway and the Barrier Highway through the Flinders Ranges, and forms the most direct path between Port Augusta in South Australia (and following destinations like Alice Springs, Darwin, Kalgoorlie, and Perth) and Dubbo (and following destinations like Moree, Tamworth, Orange, and Newcastle), and hence provides the most direct link between Port Augusta and Sydney.

Mount Remarkable National Park: Mount Remarkable National Park is a protected area in the Australian state of South Australia located about 238 km north of the state capital of Adelaide and 25 km east of Port Augusta.  It is also the name of the highest peak in the Park, with a height of 960 m .

Yorkey Crossing: Yorkey Crossing is a ford in the Australian state of South Australia located at the head of Spencer Gulf in the gazetted locality of Emeroo about 4 nmi north of Port Augusta.  As of 2014, it is the site of an unsealed road that serves as a by-pass route around the head of the gulf for 'over dimensional vehicles' (i.e. greater than 4 m wide and 5.8 m high), which are not permitted to cross the gulf using the Port Augusta Bridge.  It is also near the location of the crossing (also known as Yorkey Crossing) for the Kalgoorlie to Port Augusta Railway (now called the Trans-Australian Railway) built after 1911.  It is considered to be the most north easterly part of Eyre Peninsula.

Port Augusta: Port Augusta is a small city in South Australia.  Formerly a seaport, it is now a road traffic and railway junction city mainly located on the east coast of the Spencer Gulf immediately south of the gulf's head and about 322 km north of the state capital.  The suburb of Port Augusta West is located on the west side of the gulf on the Eyre Peninsula.  Other major industries included, up until mid-2010s, electricity generation.  At June 2015, the estimated urban population was 14,214.

Don Jessop: Donald Scott "Don" Jessop (born 21 June 1927) is an Australian former politician.  Born in Adelaide, he was educated at state schools and then the University of Adelaide, after which he became an optometrist at Port Augusta.  He was a councillor with Port Augusta City.  In 1966, he was elected to the Australian House of Representatives as the Liberal member for Grey, defeating sitting Labor member Jack Mortimer.  He was defeated in 1969, but in 1970 was elected to the Senate.  He remained in the Senate until he was defeated in 1987.

Port Augusta Town Hall: The Port Augusta Town Hall is a heritage-listed former town hall at 54 Commercial Road, Port Augusta.  It was added to the South Australian Heritage Register on 23 September 1982; it is also listed on the Register of the National Estate.

Princes Highway: The Princes Highway is a major road in Australia, extending from Sydney to Port Augusta via the coast through the states of New South Wales, Victoria and South Australia.  It has a length of 1941 km (along Highway 1) or 1898 km via the former alignments of the highway, although these routes are slower and connections to the bypassed sections of the original route are poor in many cases.

Mount Imlay National Park: Mount Imlay is a national park in New South Wales (Australia), 387 km south of Sydney, named after the Imlay brothers, who were early pioneers to the district.  It is accessed from the Princes Highway, south of Eden, New South Wales.

Strzelecki Regional Reserve: Strzelecki Regional Reserve is a protected area located in the Australian state of South Australia in the gazetted localities of Lindon and Strzelecki Desert about 493 km north-east of Port Augusta.  It includes the Strzelecki Desert and the dry Strzelecki Creek bed.  The regional reserve can only accessed via the historic Strzelecki Track.  It is partly located on land that was included on the List of Wetlands of International Importance under the Ramsar Convention under the name Coongie Lakes in 1987.  The regional reserve is classified as an IUCN Category VI protected area.

Supporting paragraphs: Mount Imlay National Park Princes Highway
Answer: New South Wales