Trout Lake is in Vilas County, Wisconsin, near the towns of Boulder Junction and Arbor Vitae, Wisconsin. With a surface area of 6.208 sq mi and a volume of 0.058 cu mi, Trout Lake is one of the largest lakes in Vilas County. It has 16.1 mi of shoreline, a large portion of which is undeveloped. There are also seven islands within the lake: Miller Isla…Trout Lake is in Vilas County, Wisconsin, near the towns of Boulder Junction and Arbor Vitae, Wisconsin. With a surface area of 6.208 sq mi and a volume of 0.058 cu mi, Trout Lake is one of the largest lakes in Vilas County. It has 16.1 mi of shoreline, a large portion of which is undeveloped. There are also seven islands within the lake: Miller Island, Zimmerman Island, Haunted Island, Easter Island, Fisk Island, Chocolate Drop Island, and an unnamed island. It is a dimictic oligotrophic lake that supports a large number of sport fish, which has made it a popular angling destination.