The 1902 LDS missionary edition first introduced the plural forests in this passage. The 1905 LDS missionary edition also read this way, as have subsequent LDS editions.
As discussed under 1 Nephi 18:25, the Book of Mormon text has instances of both the singular forest and the plural forests, where context is the determining factor. Thus for the phrase “in the forest(s)”, we get the singular whenever only one forest is expected and the plural when there are multiple forests:
There were many forests in the land of promise (1 Nephi 18:25) as well as many forests where the people of Limhi could lay in wait for the Lamanite attack (Mosiah 20:8), but there was only one forest of Mormon (Mosiah 18:30). Similarly, Enos probably went to hunt beasts in a particular forest, and thus the singular forest in Enos 1:1 is most likely correct. For additional discussion, see 1 Nephi 18:25.
Summary: Restore the original singular forest in Enos 1:3 since Enos probably would have been hunting in a single forest.