Shirley Heinze Land Trust
The Shirley Heinze Land Trust, originally known as the Shirley Heinze Environmental Fund, is a 501(c)(3) nonprofit land trust dedicated to the preservation of natural areas in Northwest Indiana. The Heinze Trust manages more than 2,100 acres of protected land in Lake, Porter, LaPorte, St. Joseph, Starke, and Marshall Counties in Indiana. Its preserves include a wide range of dune, wetland, prairie, and forest ecosystems.
Due to the heavily developed nature of the Calumet Region, many of the Heinze Trust's parcels are entirely surrounded by industrial or residential development. Many of the preserves were severely degraded when first acquired, and the Heinze Trust has engaged in a wide range of restoration activities in order to restore them to ecological viability. The Heinze Trust's preserves include five designated Indiana Nature Preserves, some of which were purchased with funds from the Indiana Heritage Trust.
The Heinze Trust was established in 1981 by an endowment from Mr. & Mrs. Robert L. Seidner. The organization was named to honor the memory of Dr. Shirley Heinze, a resident of Ogden Dunes whose efforts helped preserve the Indiana Dunes.
- Bur Oak Woods (Hobart)
- This is a 74-acre remnant of bur oak savanna.
- Cressmoor Prairie (Hobart)
- Cressmoor covers 41 acres of black-soil prairie, and is one of only three significant remnants of this type of prairie in Indiana. It is home to more than 180 native species of prairie plants. Purchased with funds from the Indiana Heritage Trust, the preserve was dedicated in October 1996.
- Hobart Marsh Complex (Hobart)
- This complex of wetlands and wet prairie covers 357 acres, and includes the Hidden Prairie preserve.
- Ivanhoe South (Gary)
- This preserve is immediately across US 20 from the Nature Conservancy's Ivanhoe Dune and Swale preserve. Like its namesake, it provides Karner Blue habitat and is home to numerous species of rare native plants.
- Seidner Dune & Swale (Hammond)
- The westernmost major holding of the Heinze Trust, the Seidner Dune and Swale is one of the few remaining remnants of the freshwater dune and swale ecosystem that once dominated the landscape of the Tolleston Strand Plain. It covers 144 acres, sandwiched between the Indiana Toll Road and the Grand Calumet River. Over 250 species of plants have been identified at the preserve. This is one of three major preserves in the Tolleston Strand Plain, the others being the Nature Conservancy's Ivanhoe preserve and Lake County's Gibson Woods.
- John Merle Coulter Sand Prairie (Portage)
- The Coulter Sand Prairie covers 90 acres, and lies directly south of the Tolleston Dunes area of the Indiana Dunes National Lakeshore. Originally dominated by high dunes, the property was heavily sand mined in the 1930s, and is thus largely flat today. The preserve is home to 19 endangered species, including the endangered Karner Blue butterfly, but has required management against overgrazing by white-tailed deer. 
The preserve takes its name from pioneering Chicago-area botanist John Merle Coulter.
- Great Marsh (Beverly Shores)
- Little Calumet Wetlands(Chesterton)
- Meadowbrook (Valparaiso)
- Walnut Woods(Valparaiso)
- Ambler Flatwoods (Michigan City)
- This 390-acre woods was dedicated as a state nature preserve in 2006. It is home to 365 different plant species, many found nowhere else in the state, as well as the rare Blanding's Turtle.
- Barker Woods (Michigan City)
- Property listed on the National Register of Historic Places in 2001 as the Barker House.
- Hildebrand Lake (Westville)
- Adelman, Charlotte (2013). Prairie Directory of North America. p. 117. ISBN 9780195366952.
- Schoon, Kenneth J. (2013). Dreams of Duneland: A Pictorial History of the Indiana Dunes Region. ISBN 9780253007988.
- "About Us". Shirley Heinze Land Trust. Retrieved 2014-03-06.
- Schoon 2013, p. 270.
- Schoon, Kenneth J. (2003). Calumet Beginnings. p. 219. ISBN 978-0-253-34218-8.
- "History". Shirley Heinze Land Trust. Retrieved 2014-03-06.
- Shirley Heinze Land Trust; pamphlet, 2013
- Adelman 2013, p. 117.
- The Nature Conservancy (1999). The nature conservancy: a guide to Indiana Preserves and projects.
- Crawford, Mark (1999). Habitats and Ecosystems: An Encyclopedia of Endangered America.
- "Current Programs to Increase or Improve Recreational Opportunities". State of Indiana. Retrieved 2014-03-06.
- Adelman 2013, p. 118.
- Griffin, Jake (2009-08-30). "Naturalist treks 200 miles to our diverse, urban landscapes". Daily Herald.
- Staff (2010-07-09). "National Register Information System". National Register of Historic Places. National Park Service.