The Marfell Lakes (1 and 2) are reservoirs in

Boulder County Boulder County is a county located in the U.S. state of Colorado of the United States. As of the 2020 census, the population was 330,758. The most populous municipality in the county and the county seat is Boulder. Boulder County comprises th ...

near Lafayette-Louisville in the U.S. state of

Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...

. The altitude is .

References

Reservoirs in Colorado Bodies of water of Boulder County, Colorado {{Colorado-geo-stub