Indiana Dunes National Park in the context of Lake County, Indiana

Gary is a city in Lake County, Indiana, United States. The population was 69,093 at the 2020 census, making it Indiana's eleventh-most populous city. The city has been historically dominated by major industrial activity and is home to U.S. Steel's Gary Works, the largest steel mill complex in North America.

Gary is located along the southern shore of Lake Michigan about 25 miles (40 km) southeast of downtown Chicago. The city is the western gateway to the Indiana Dunes National Park, and is within the Chicago metropolitan area.

Indiana Dunes State Park is an Indiana State Park located in Porter County, Indiana, United States, 47 miles (75.6 km) east of Chicago. The park is bounded by Lake Michigan to the northwest and is surrounded by as well as within the authorized boundaries of Indiana Dunes National Park, a unit of the National Park Service; the NPS owns the water from the ordinary high water mark to 300 feet (91 m) offshore. The 1,530-acre (619.2 ha) Dunes Nature Preserve makes up the bulk of eastern part of the park, and includes most of the park's hiking trails and dune landscape. This was one of the first places Richard Lieber considered when establishing the Indiana State Park system. Like all Indiana state parks, there is a fee for entrance. Indiana Dunes State Park was established in 1925 and designated a National Natural Landmark in 1974.

Preserving the Indiana Dunes has resulted from the efforts of many citizens and politicians. In 2018–2019, Indiana Dunes was the most-visited Indiana state park, with more than 1.3 million visitors.

U.S. Route 12 (US 12) is a part of the United States Numbered Highway System that runs from Aberdeen, Washington, to Detroit, Michigan. In the U.S. state of Indiana, it is part of the state road system. US 12 enters the state concurrent with US 20 and US 41 in Hammond. The 46.258 miles (74.445 km) of US 12 that lie within Indiana serve as a major conduit. Some of the highway is listed on the National Highway System (NHS). Various sections are rural two-lane highway, urbanized four-lane undivided highway, and one-way streets. The easternmost community along the highway is Michiana Shores at the Michigan state line.

US 12 passes through urban areas and wood lands, parallel to the Lake Michigan shoreline. The highway is included in the Lake Michigan Circle Tour and passes through Indiana Dunes National Park. Historical landmarks along the highway include the Miller Town Hall, Beverly Shores station, and the Old Michigan City Light. A memorial highway designations have been applied to the route since 1917, named for the Civil War Union Army unit.

Michigan City is a city in LaPorte County, Indiana, United States. It had a population of 32,075 at the 2020 census. Located along Lake Michigan in the Michiana region, the city is about 45 miles (72 km) east of Chicago and is 40 miles (64 km) west of South Bend.

Michigan City is noted for both its proximity to Indiana Dunes National Park and for bordering Lake Michigan. It receives a fair amount of tourism during the summer, especially by residents of Chicago and nearby cities in Northern Indiana. It is connected to Chicago via the South Shore Line passenger train.

Pinhook Bog is a unique bog in Indiana that has been designated a National Natural Landmark. It is part of Indiana Dunes National Park, an area that many citizens, scientists, and politicians fought hard to preserve. Its sister bog, Volo Bog (not to be confused with a bog of the same name in Illinois), is located nearby. The bog contains a large variety of plants, including insect eating plants, tamarack trees, stands of blueberry bushes, and floating mats of sphagnum moss. Pinhook Bog is about 580 acres (2.3 km), a quarter of which is a floating mat of sphagnum peat moss. A "moat" separates the bog from the uplands.

Hoosier Prairie is a unit of Indiana Dunes National Park in Lake County, Indiana. It began in the 1970s as wasteland that the Hoosier Prairie Committee founded by Irene Herlocker-Meyer found of unique interest. From a core of 304 acres (123 ha), it has grown to 1,547 acres (626 ha) of important prairie habitat. The area was designated a National Natural Landmark in 1974 and a State Nature Preserve in 1977 The sandy soil creates a variety of habitats, from oak barrens, wet prairie, including sedge meadows and prairie marshes. More than 350 native species of vascular plants have been identified. A minimum of 43 species are uncommon in the State of Indiana.

Marquette Park, originally called Lake Front Park, is a municipal park completely surrounded by Indiana Dunes National Park. Its primary features include 1.4 miles (2.2 km) of Lake Michigan beaches, inland ponds, sand dunes, wetlands, a lagoon, and indigenous oak savanna. The park is located within the Miller Beach community. The park includes the Octave Chanute museum, registered as a National Landmark of Soaring.