The Northpoint reservoir was built in the northern reaches of the region, designed to regulate the flow of water into the valley and allow for the construction of Nuka-World.
Since the Great War, the reservoir's dam still stands strong, but neglect and environment changes have blocked the flow of the water. The stagnant water has attracted a group of mirelurks, including a mirelurk queen.
The small pond at the foot of the dam is filled with mirelurks. When all of them are killed, a mirelurk queen will appear in the middle of the pond. There is a small, abandoned office building and house on the west bank of the river. Near where the mirelurk queen spawns is a rowboat with several Nuka-Colas and a duffle bag.
With a few jumps, the Sole Survivor can get up on the dam, but only on the left side. This is because the dam is right on the edge of the map border.