The game reserve was built in 1969 after the Deininghausen settlement was built. The city of Castrop-Rauxel acquired the Grutholz in 1963 and began to develop the forest as the largest recreational area close to the city. The enclosure is about 4 hectares. In addition to forest areas, it also encloses green areas and gives the game ample opportunities to retreat. In 1969 it housed ten fallow deer.
2004 threatened the end for the enclosure. For financial reasons, the city wanted to sell forest areas and close the game reserve. Three citizens did not want to accept it. After a citizen's application for the preservation of the enclosure was rejected by the council in March 2004, they carried out a referendum with the question: "Should the game enclosure in Grutholz be preserved?" With the help of numerous citizens, 7751 signatures were collected. An impressive vote that the city council couldn't get around. In July 2004 the city council voted unanimously in favor of the preservation of the enclosure.
The citizens founded the non-profit "Förderverein Wildgehege Grutholz e.V." Animals have a future again and people, including many families with children, have the opportunity to relax in a natural environment.
The development association maintains the municipal enclosure. Citizens take on the care and feeding of the animals on a voluntary basis and keep the enclosure in order. The association covers the costs from donations, membership and sponsorship contributions as well as the proceeds from campaigns.
Source: Grutholz game reserve