Mattatall Lake is located in rural west-central Nova Scotia, Canada on the border between Cumberland and Colchester counties, approximately 10 km WSW of the historic village of Tatamagouche. The family name of Mattatall refers to French speaking immigrants from the principality of Montbéliard, now in eastern France, near the border with Switzerland, who settled in the Tatamagouche area in 1771. This group originally came to Nova Scotia in 1750-52 as part of the ‘the Foreign Protestants’, including other German speaking groups that founded the town of Lunnenberg. The lake covers approximately 120 hectares (300 acres) in three connected lobes and is now primarily used for both summer and winter cottage recreation. It is also known as a primary spot for bass fishing (see recreational information under Links).

The Mattatall Lake Stewardship Association (MLSA) is a registered non-profit organization with its mission to support all measures of protecting the water quality of Mattatall Lake and its surrounding watershed.  The MLSA was formed in 2015 in response to evidence of a severe threat to its water quality.  Harmful blue-green algal blooms have occurred in the lake in 2014-16, but were absent in 2017.

The MLSA has a paid membership of approximately 50 members and is led by a rotating board of 9 volunteers. An annual general meeting (AGM) is held each summer to elect new board members and endorse its yearly operations and budget. Newsletters are sent to members on a biannual basis or as required. The organization has collaborated with research groups at the Agricultural College and Department of Civil & Resource Engineering at Dalhousie University, and with the Nova Scotia Department of the Environment. Local volunteers have worked in the lake to support research activities, reduce motorboat disturbance, educate lake shore residents about best environmental practices and raise awareness among watershed stakeholders on the downstream impacts of land use. Further details are given in the Projects & Research section.

The Association also advocates through its work to help foster water quality in other Nova Scotia lakes. The Association extends its awareness of lake management issues through membership in the North American Lake Management Society (NALMS).