Hermidale is a town within the local government area of the Bogan Shire in the Orana region of New South Wales. The shire is adjacent to the Mitchell and Barrier highways. In 1906, the Bogan Shire was incorporated. It was subsequently merged with the Nyngan Municipality in 1972. Hermidale is near the Bogan River, a minor river that was discovered by Charles Sturt in 1829. It runs from near Forbes and flows northwest past Nyngan. The town is also near the Macquarie Marshes, a wetland system that covers about 220,000 hectares of land. It is known as one of the largest semi-permanent wetlands in south-eastern Australia, boasting of a huge variety of aquatic plants and waterbirds, including egrets, cormorants, spoonbills and many others.