Spednic Lake (sometimes Spednik Lake or Spednick Lake) is a mesotrophic lake in the Chiputneticook Lakes chain along the Canada–United States border between the state of Maine and the province of New Brunswick that is best known for its bass fishing. Sometimes it is viewed as the headwaters of the St. Croix River, sometimes a lake further up the chain is considered the headwaters. The international border runs through the lake. A northeastern arm of the lake, located entirely in Canada, retains the name Palfrey Lake. Prior to dam construction that expanded Spednic Lake they were separate lakes, but now they are hydrologically and ecologically a single combined lake.
The first dam at the outlet of the lake was constructed in 1836 with a 15-foot (4.6 m) impoundment level. Over the years the dam has been modified and is now known as the Vanceboro Dam. Waterflow from this dam and others upstream are regulated by the International St. Croix River Board that is appointed by the International Joint Commission between the United States and Canada.
The lake shores are primarily undeveloped, and held in conservation or protected status, either through land ownership or easement, by the state of Maine and the province of New Brunswick. Small portions remain in private hands. The principal access in Maine is via a public boat launch in the town of Vanceboro. Canoes can also be portaged from elsewhere in the watershed.
