The museum houses collections totaling about 3 million specimens and representing the disciplines of paleontology, paleobotany, geology, botany, entomology, ichthyology, herpetology, ornithology, and mammalogy. They are used extensively both in research and as the basis for educational programs and exhibits. The bulk of the collections are comprised of important voucher specimens and are invaluable resources for documenting the natural history of the Great Plains. The Sternberg Museum serves as a regional depository and tissue bank for many taxa.

Most of the collections are from the Great Plains and adjacent areas, but reference collections from other regions are maintained to facilitate taxonomic, systematic, and molecular research and for educational purposes. The initial paleontological collections were amassed by George Sternberg during his association with Fort Hays State University. The world famous Elam Bartholomew Herbarium botanical collections developed as a result of research by mycologist Elam Bartholomew. Collections continue to grow as the result of research and collaboration by curators associated with the museum and with the departments of geology and biology at Fort Hays State University as well as discoveries by landowners and fossil hunters around the country.

Paleontology. A conservative estimate of the total number of fossil specimens would be 100,000 vertebrates; 300,000 invertebrates. The paleontology collection includes a large collection of Cretaceous marine vertebrates and the 3rd largest collection of pterosaurs in the world. It also contains a large collection of Miocene and Pleistocene vertebrates. There is also a representative collection of Cretaceous marine invertebrates. There are 38 type specimens in the paleontology collection.

Paleobotany. More than 100,000 fossil plant specimens are located in this collection, nearly all of which are vascular plants.  It contains an outstanding representation of fossil plants from the Great Plains, plus the largest collection of fossil grasses in the world, including over 1,000 primary types. Especially well represented groups are Tertiary Gramineae, Cyperaceae, Boraginaceae, Ulmaceae and other flowering plants and various Paleocene and Cretaceous flowering and non-flowering plants.

Geology. The Geology collection consists of representative samples of the major mineral and rock groups.  The most important part of the collection is the meteorites and tektites.  The museum has a sample of nearly 85% of the meteorites that have fallen in Kansas.  There is also a small exhibit of fluorescent minerals.  This collection is inactive. The last specimens were collected in the mid-90s to provide specimens for exhibits in the new Museum.

Botany. More than 48,000 specimens of primarily angiosperms are housed in the world famous Elam Bartholomew Herbarium.  The Plains region of central North American is especially well represented, although significant exchange programs conducted by Bartholomew from 1887 – 1932 and F. W. Albertson from 1934 -1942 incorporated important elements of other regions in the collection. The Herbarium also houses more than 10,000 fungal specimens, including 66 primary types, collected by Elam Bartholomew and contemporaries between 1887-1934 and consists primarily of rust fungi on host vascular plants.

Entomology. The Entomology Collection contains more than 100,000 insects, representing nearly all North American families but emphasizing Lepidoptera.

Ichthyology. The Ichthyology Collection consists of nearly 700,000 specimens, primarily from the Great Plains. Because of recent contracts with both state and federal wildlife agencies, this collection is rapidly growing and has become a major regional depository for Great Plains fishes.

Invertebrate (non-insect). This relatively new collection consists of a wide variety of primarily aquatic invertebrates, excluding insects. Freshwater Mollusks and Crustaceans make up the bulk of this group. The majority of the nearly 300 specimens are vouchers from faculty or graduate student research and regional surveys.

Ornithology. The Ornithology Collection houses nearly 4,500 specimens, primarily consisting of important voucher specimens. This collection also boasts an excellent representation of variation in many Great Plains taxa.

Herpetology. The Herpetology Collection contains over 17,000 amphibians, reptiles, and turtles and is growing at a rapid rate with regional voucher specimens. Most specimens are fluid preserved, with some specimens represented by skeletons and skins. The Sternberg Herpetology tissue bank contains over 10,000 preserved tissue samples of most North American taxa. These tissues are used extensively in molecular and DNA-based research, including systematics, phylogeography, and evolution.

Mammalogy. Over 40,000 specimens, including 2 holotypes, are housed in the Sternberg Mammalogy Collection. It is one of the most intensively used research collections in the U.S. The Sternberg Mammalogy tissue bank contains over 2,000 preserved tissue samples, primarily from Kansas. These tissues also are used extensively in molecular and DNA-based research, including systematics, phylogeography, and evolution.