Иногда это правило даже специально приводится в контрасте с артиклями для полуостровов, где просто название идет без артикля, e.g. Scandinavia, а если слово Peninsula добавить, то и артикль ставить надо - the Scandinavia Peninsula ...

А в какой грамматике the Lake Baikal в правиле написано?

March 2001
U.S. Water News Online

MOSCOW -- Russia has boosted funding for the protection of Siberia's Lake Baikal, the earth's oldest and deepest lake, the ITAR-Tass news agency has reported.

More than $3.2 million, or one-third more money than last year, will be spent on conservation efforts for the lake in 2001, said agency spokesperson Valery Molotov, head of the Lake Baikal water resource management committee.

Molotov said his committee was planning to draft legislation that would regulate water levels and fishing and prohibit certain activities around the lake, ITAR-Tass said.

Lake Baikal, which UNESCO has named a world heritage site, has been plagued by pollution from a paper mill on its shores. Rampant poaching threatens its trademark inhabitant, the world's only species of freshwater seal. Last year, local authorities announced plans to drill for gas around the lake, angering environmentalists.

Sustainable Management

Law on Lake Baikal Protection and Problems with its Implementation
Dr. Alexander G. Lubsanov, Head of the Committee of Parliament for Economical Policy, Nature Use and Protection of the Environment, Russia

Nature use and environmental protection in Buryatia, elaboration of a national strategy, discussion of ecologically safe development of the Republic, consolidation of industrial and public organizations' activity and the society on the whole these are the problems that are becoming more and more urgent nowadays. That is why the Peoples' Parliament Committee of Economic Policy, Mineral Resources' Use and Environmental Protection in the Republic of Buryatia has been giving a special attention to these issues since the day of its foundation.

Lake Baikal`s uniqueness poses additional responsibility on all public authorities for protection of this natural property. This explains the activity and concern of deputies of the Committee of Economic Policy in the discussion of the Federal Law "On Lake Baikal Protection". They started working on it in 1991 and made great efforts to settle all disputable questions. In this connection the Peoples' Parliament of the Republic of Buryatia put into its agenda the discussion of the law draft. The Law on Lake Baikal Protection focuses primarily on establishing a legal, economic and organizational basis for the work aimed to preserve, restore and use rationally natural resources of the lake and adjoining territories.

The most important research area of this project is Lake Baikal. We are planning systematic investigations of hydrochemical and biological conditions in the research area, which can be used in ecological forecasts for the development and improvement of security measures against water pollution. Lake Baikal is a paradox among the worlds large lakes. The character of its organic substance cycle, the degree of utilization of solar energy by phytoplankton, and the efficiency of biotransformation of organic substances are all qualities of Lake Baikal that do not fit the models based on other large lakes. The absolute values for the primary production of the lake per unit of its water mass volume would lead one to classify this lake as oligotrophic in type (low in nutrients; sparse plant and animal life) where the pelagic ecosystem of open water plays the main role in substance cycling. Biological and physical processes occurring in this open water ecosystem are predominantly biological production, with enrichment of water with oxygen, and the destruction of organic substances creating efficient self-purification processes. All of these are based on the vital activity of the Baikalian endemic organisms united by their food relations in several trophic levels. http://www.earthwatch.org/expeditions/taganov_02/theproject.html

Прошу прощения у всего community... Этим солнечным утром жизнь казалась простой и незамороченной, вот и возникла "легкость в мыслях НЕОБЫКНОВЕННАЯ"... :-(

Действительно:

There is no article:
...
with the names of individual mountains, lakes and islands:
Mount McKinley is the highest mountain in Alaska.
She lives near Lake Windermere.
Have you visited Long Island?

Еще раз прошу прощения.