Did you know that Round Valley was once a volcano? Well, it was - but that was early in the formation of the earth. There is no history of it exploding as volcanoes do, so we can probably say that it was active when dinosaurs roamed the earth.
We know that the American Indians lived in the valley more than three thousand years ago. Spear points and ax heads have been found that experts have dated to that time. There are legends that Round Valley was the home of an Indian King and that there were Indian burial sites along the top of the mountain. These are legends, but they may be true.
During the Revolutionary War several New Jersey families had farms in the valley. These people were patriots, that is, they believed that our country should be free of English rule. The Stevens family was one of these wealthy families. Because the English soldiers were trying to capture important people, the Stevens men sent their women and children to live at their homes in the valley. Round Valley was very safe and could be easily defended because there was only one natural entrance. After the Revolutionary War the Stevens moved to Hoboken, New Jersey, where they founded the Stevens Institute of Technology, a very famous college, even today. They built a railroad, and invented many things such as the steamboat.
Farmers continued to live in Round Valley until the State of New Jersey bought the whole valley in the 1950's. It was purchased to become a reservoir because the people in cities to the east needed pure drinking water. Round Valley was the only natural valley in northwest Jersey big enough to become a reservoir. It was during the 1960's that all of the farm houses were either moved out or torn down, and the valley was filled with water.
Today it is a beautiful lake and park - open to all of the people of New Jersey. The water from it is pumped downstream to the cities of our state.
Source: Beneath These Waters, by Stephanie B. Stevens
The Round Valley Trout Association