A variety of depositional environments are represented in the succession, including floodplains, estuarine channels, and coal swamps, which have yielded a diversity of fossil material.

Tidally-influenced estuarine point bar deposits are easily recognizable as Inclined Heterolithic Stratification (IHS).

Brackish-water trace fossil assemblages occur within these bar deposits and demonstrate periodic incursion of marine waters into the estuaries.

[5] In more recent times, the Horseshoe Canyon Formation has become a major target for coalbed methane (CBM) production.

Dinosaurs found in the Horseshoe Canyon Formation include Albertavenator, Albertosaurus, Anchiceratops, Anodontosaurus, Arrhinoceratops, Atrociraptor, Epichirostenotes, Edmontonia, Edmontosaurus, Hypacrosaurus, Ornithomimus, Pachyrhinosaurus, Parksosaurus, Saurolophus, and Struthiomimus.

Other finds have included mammals such as Didelphodon coyi, non-dinosaur reptiles, amphibians, fish, marine and terrestrial invertebrates and plant fossils.

Reptiles such as turtles and crocodilians are rare in the Horseshoe Canyon Formation, and this was thought to reflect the relatively cool climate which prevailed at the time.

A study by Quinney et al. (2013) however, showed that the decline in turtle diversity, which was previously attributed to climate, coincided instead with changes in soil drainage conditions, and was limited by aridity, landscape instability, and migratory barriers.

It contains 10 to 20 metres of cumulative coal, in up to 20 or more individual thin seams interbedded with sandstone and shale, which combine to make an attractive multi-completion CBM drilling target.

[7] Anodontosaurus[8][9] A. lambei[8][9] Horsethief, Morrin, and lowest Tolman[8][9] An ankylosaurine ankylosaurid also known from the middle Dinosaur Park Formation and closely related to Ankylosaurus.

Edmontonia[11] E. longiceps[11] Upper Horsethief[11] A panoplosaurin nodosaurid also known from the lower Dinosaur Park Formation and closely related Denversaurus.

[18] Eotriceratops[19] E. xerinsularis[19] Carbon[19] Premaxillae, maxillae, rostral, supraorbital horncore with lacrimal, prefrontal, frontal, postorbital, jugal, epijugal, quadratojugal, quadrate, partial parietal, squamosal frill, braincase, syncervical, cervical vertebrae, dorsal vertebrae, ribs and fragments of ossified ligaments.

[28] Atrociraptor[29] A. marshalli[29] Lower Horsethief[29] Premaxillae, maxilla, dentaries, teeth and numerous bone fragments.