Greenhorn Reservoir, located in Yreka, California, is a vital water resource managed by the local government for water supply and recreation purposes. The earth dam, completed in 1960, stands at a height of 35 feet and has a storage capacity of 251 acre-feet. Situated on Greenhorn Creek, the reservoir covers an area of 25 acres and serves as a key source of water for the surrounding community.

With a high hazard potential, the dam undergoes regular inspections by the Department of Water Resources to ensure its structural integrity. The latest assessment in September 2017 deemed the dam's condition as satisfactory, providing confidence in its ability to withstand potential risks and emergencies. Despite its critical role in water management, the reservoir also offers recreational opportunities for visitors to enjoy the scenic beauty of the area.

Managed by the Natural Resources Conservation Service, Greenhorn Reservoir plays a crucial role in water supply and environmental conservation efforts in the region. As climate change continues to impact water resources, the sustainable management of reservoirs like Greenhorn becomes increasingly important to ensure the resilience of communities and ecosystems in the face of evolving environmental challenges.