Prior to the completion of the Castle Rock Dam in 1951, the area held farmlands, vast prairies, and forested knolls separated by the Wisconsin River.

[3] The Wisconsin River Valley supported human life for over 10,000 years, and was inhabited by Indigenous Ho-Chunk and Menominee people.

[4] The artwork varies in drawings including birds, canoes, animal tracks, phases of the moon, and man.

[4] Archeologists claim that the pictures were painted after 900 A.D.[4] The Ho-Chunk people were believed to have used these portrayals for an assortment of purposes including record keeping, storytelling and even politics.

[4] While the exact translation may have been lost, similar to the effigy mounds, they both tell a unique history about the people who first inhabited the area around Castle Rock Lake.

[7] Maximum fetch:(km): 16.371 km[1] Maximum surface wave height(m): 1.34m[1] Minimum water temperature (°C): 1.9 °C[8] Maximum water temperature (°C): 28.2 °C[8] Daily total undepleted solar radiation (cal cm−2 day−1) by season: Average percentage sunlight reflected: Secchi disk depth (m):1 m (3.3 ft.)[8] The equilibrium concentration of dissolved oxygen in the surface waters at varying temperature are: The average pH of Castle Rock Lake is 7.2[10] The total dissolved organic carbon is 17 mg L−1[1] The chlorophyll a levels are: 6 μg L−1[8] Total alkalinity (mg/L and meq/L): 32 (mg/L)[10] Hardness (mg/L): 91 mg/L[11] The aquatic plant life of Castle Rock Lake is essential to the fish and other fauna that inhabit the lake.

[16][2] The lake is also known for being a winter refuge for bald eagle and a location the Wisconsin DNR is attempting to bring back wild osprey and wood duck populations too.

[3] The area surrounding Castle Rock Lake creates a habitat for many animal species, including a wide range of amphibians, mammals, and reptiles.

[14] Castle Rock Lake has encountered several environmental concerns including, blue-green algae, invasive species, and shoreline development.

[17] Blue-green algae can have negative impacts on both humans and animals, water with obvious algal blooms should be avoided.

Blue-green algae (also known as Cylindro), Eurasian water-milfoil, and zebra mussel are the three invasive species noted by the Wisconsin Department of Natural Resources.

This plant is native to Europe, Asia, and North Africa, it likely found its way to the United States through the aquarium trade or watercraft.

[20] There are Environmental Protection Agency and Wisconsin Department of Natural Resources projects in place to create solutions that will lower the rate of phosphorus pollution into the waterways.

[2] Castle Rock Lake is also a huge resource for the surrounding areas because of the hydroelectric dam located on the southern shoreline which provides energy to nearby settlements.