Horton Falls National Park CCA Zone 1 is 260 hectares. The boundaries of the national park are straight lines based on cadastral boundaries rather than landscape features. The Part 11 lands comprise 40 hectares.
Horton Falls National Park CCA Zone 1 was reserved on 1 December 2005 under the Brigalow and Nandewar Community Conservation Area Act 2005.
The park is an important refuge for an array of forest species that are characteristic of the western tablelands, slopes and Mount Kaputar region. The ecological significance of the park is greatly enhanced because the surrounding landscape has been extensively cleared for agriculture. Species diversity within the park is high, most likely due to the undisturbed nature of the communities present, particularly those occurring in the northern half of the national park. There are old-growth forests, with many trees containing multiple hollows. The park also supports high quality riparian areas. The park is known to protect the threatened squirrel glider (Petaurus norfolcensis) and five threatened bird species, including the regent honeyeater (Anthochaera phrygia) which is critically endangered and of state and national significance.
The low incidence of fire is also significant to the biodiversity of the park, allowing the spread of sweet pittosporum (Pittosporum undulatum) and associated dry rainforest species. These species are usually restricted to very narrow zones along creeks and rivers in the area due to the high frequency of fire in the region.