Long Lake, located in Hoffman, Minnesota, is a state-regulated water resource managed by the Minnesota Department of Natural Resources. This reservoir on the Chippewa River was completed in 1938 and serves various purposes, with a primary dam type of "Other" and a buttress core type. The dam stands at a height of 6 feet and has a hydraulic height of 1.9 feet, with a storage capacity of 2255 acre-feet and a surface area of 218 acres.

With a drainage area of 143 square miles, Long Lake has a low hazard potential and is in satisfactory condition according to a 2009 assessment. The reservoir has a normal storage capacity of 1640 acre-feet and a maximum discharge of 1470 cubic feet per second. Despite being unlisted for spillway type and having no associated locks, Long Lake provides valuable water resources for the region and is subject to state inspection, permitting, and enforcement to ensure its safety and efficiency for water and climate enthusiasts.