Directions: Lake Mary is located in Salt Lake County, Utah in Big Cottonwood Canyon.
The Trail: Park at Brighton Ski Resort near the main lodge. The trail goes in between the Majestic and Crest ski lifts. The hike is about 1 mile to lake. The first part is pretty steep but overall the hike is fine for fat adults and small children with good attitudes. Summit Post has a good article on the hike here.
Fish Species: Brook Trout, Lake Trout
Regulations: Since the reservoir is used for drinking water, it is closed to swimming or wading. The Reservoir is also closed to non service dogs.
History: Lake Mary was named after the daughter of Catherine Bow Brighton, who was named Mary. Catherine and her husband William S Brighton migrated to Big Cottonwood Canyon from Scotland. Their daughter died on the ship from Scotland to the United States at the age of two. The ski resort was named after the Brighton family who operated a hotel there. If you want to read more about this check out Balsam Hill Cabin, written by Rod Morris. There is a ton of history on this site, with some good pictures too.
Lake Mary-Phoebe Dam: There used to be two different lakes which were Lake Phoebe and Lake Marry. There was a dike separating the two that was 15 to 20 feet tall. A dam was constructed on the outlet of Lake Phoebe between 1913 and 1915. In order to increase the amount of drinking water supplied for the Salt Lake Valley. This dam combined the two reservoirs into one. At first the dam was going to be built out of granite. Although it was quickly discovered that concrete was stronger than granite. Most of the concrete was delivered from horses coming from Park City. Even though they did have motor cars at the time, horses proved to be more cost effective. In 2010 much of the lake was drained in order to fix an outlet gate.