Lake Theriot is a private lake located in Terrebonne County, Louisiana, accessible only through a gated canal from Marmande Canal. The lake sits within the fresh-to-brackish marshes of the Barataria-Terrebonne estuary system and is part of the extensive wetland network that characterizes this region.

Access to Lake Theriot for paddling is restricted, as it is private property with a gated entrance. The lake can be viewed from the adjacent Marmande Canal, which runs for four miles through the area and connects to the community of Theriot via Bayou DuLarge. The Marmande Canal route is part of an 11-mile shuttle trip that begins at Cannon's Boat Landing in Waterproof and ends at a parish launch in Theriot.

The surrounding area features the Mandalay National Wildlife Refuge, which encompasses extensive marsh habitat supporting diverse bird populations, fish, and alligators. The landscape is characterized by the old Marmande cheniere - a forested ridge of mature oak trees that provides habitat for various wildlife species typical of cheniere environments.

Paddlers in the area should be aware that this is a tidally influenced system, with hyacinth rafts that move with tidal flow and can create blockages near canal mouths. The marshes experience strong sun exposure with minimal shade, and biting flies, particularly salt-marsh mosquitos, can be problematic. Navigation can be challenging in this marsh environment, especially after dark.

The region is part of the historic Barataria-Terrebonne estuary, which has supported human occupation for thousands of years and continues to sustain active fishing, shrimping, and crabbing industries. While Lake Theriot itself is not accessible for public paddling, the surrounding waterways offer opportunities to experience this unique Louisiana coastal ecosystem.