Ritter (Large) is a privately owned dam located in Bonanza, Oregon, along the Wildhorse Creek. Built in 1903 for irrigation purposes, this earth dam stands at a height of 29.7 feet with a hydraulic height of 24 feet and a structural height of 35 feet. It has a storage capacity of 293 acre-feet and covers a surface area of 47 acres. Despite being classified as having a low hazard potential, the dam is subject to state regulation, inspection, and enforcement by the Oregon Water Resources Department.

The dam features an uncontrolled spillway and is equipped with slide (sluice gate) outlet gates. With a maximum discharge capacity of 942 cubic feet per second, Ritter (Large) serves the surrounding area for agricultural irrigation needs. While it has not been rated for its condition, the dam is considered to have a moderate risk level, indicating the importance of ongoing risk management measures.

The last inspection of Ritter (Large) was conducted in August 2017, with a scheduled inspection frequency of every 6 years. Situated within the Klamath County of Oregon, this dam plays a vital role in water resource management and agriculture in the region. Enthusiasts of water resources and climate will find Ritter (Large) to be a fascinating example of early 20th-century engineering contributing to sustainable water usage in the area.