Peña Blanca Lake is a reservoir in Arizona, United States, located 18 miles (29 km) northwest of Nogales.

[2] In 2008, the lake was closed to clean mercury contamination within the sediment, thought to be from old mines in the area.

[4] In 2013, an Arizona Department of Environmental Quality report showed that mercury levels were similar to those before the lake was drained and dredged.

[6] Before Peña Blanca Lake was drained the fish population consisted of largemouth bass, bluegill, redear sunfish, green sunfish, black crappie, channel catfish, and black bullhead.

Today the fish species that inhabit the lake are channel catfish, yellow bullhead, largemouth bass, bluegill, black crappie, and redear sunfish.