The Bloomingdale Trail is a 2.7-mile (4.3 km) elevated rail trail linear park running east–west on the northwest side of Chicago. It is the longest greenway project of a former elevated rail line in the Western Hemisphere, and the second longest in the world, after the Promenade plantee linear park in Paris. In 2015, the City of Chicago converted the former Bloomingdale railway line to an elevated greenway, which forms the backbone of the 606 trail network. The Bloomingdale Trail elevated park is in the Logan Square, Humboldt Park, and West Town community areas.

A linear park is a type of park that is significantly longer than it is wide. These linear parks are strips of public land running along canals, rivers, streams, defensive walls, electrical lines, or highways and shorelines. Examples of linear parks include everything from wildlife corridors to riverways to trails, capturing the broadest sense of the word. Other examples include rail trails, which are disused railroad beds converted for recreational use by removing existing structures. Commonly, these linear parks result from the public and private sectors acting on the dense urban need for open green space. Linear parks stretch through urban areas, coming through as a solution for the lack of space and need for urban greenery. They also effectively connect different neighborhoods in dense urban areas as a result, and create places that are ideal for activities such as jogging or walking. Linear parks may also be categorized as greenways. In Australia, a linear park along the coast is known as a foreshoreway. When being designed, linear parks appear unique as they are planned around the public's opinion of how the space will affect them.