The Blackroot Vale (S. "Morthond Vale") was a valley of rich grassland through which the River Morthond flowed. The river rose in a small valley beneath the sheer mountainsides of the White Mountains' southern extent, and in the shadowed rocks above its spring was the hidden gateway leading out from the Paths of the Dead.
Portrayal in Adapations
2014: The Lord of the Rings Online:
The people of the vale were known in Gondor for their archery skills, and their lord Duinhir took a small company of his bowmen to the Battle of the Pelennor Fields. With them went Duinhir's sons, Derufin and Duilin, both of whom were lost in the defence of Minas Tirith.
On 8 March T.A. 3019, Aragorn, Gimli, Legolas, and the Grey Company exited the Paths of the Dead at the source of the Morthond. They rode to the Stone of Erech where Aragorn, as the heir of Isildur, called upon the Oathbreakers to follow him and fulfill their pledge.