Dickinson Park is a difficult-to-access remote subalpine parkland in the Shoshone National Forest of Wyoming; it is located on the east slope of the Wind River Range (Central Rocky Mountains), immediately south of the Wind River Indian Reservation. The area has never been previously visited by bryologists. As a result of a bryological inventory conducted in the Park in 2012 (and subsequent laboratory research through 2019), 121 species, three subspecies, and five varieties were documented by voucher specimens. Of this total, 17 species, three subspecies, and two varieties are hepatics and 104 species and three varieties are mosses. The bryophyte checklist is presented, based on 990 specimens from 35 sites, collected by the author. Fourteen species of mosses have not previously been reported for Wyoming in the Flora of North America North of Mexico. There are 89 taxa (10 species, two subspecies, and one variety of hepatics and 74 species and two varieties of mosses) that are reported new for Fremont County. Three regionally rare species are documented on intact habitat sites of eutrophic fens located within the Park, Meesia triquetra, Paludella squarrosa, and Sphagnum angustifolium; their distribution in Wyoming is updated, based on recent publications and new herbarium materials.