Radiocarbon (C-14) provides a way to date material that contains carbon with an age up to similar to 50,000 years and is also an important tracer of the global carbon cycle. However, the lack of a comprehensive record reflecting atmospheric C-14 prior to 12.5 thousand years before the present (kyr B. P.) has limited the application of radiocarbon dating of samples from the Last Glacial period. Here, we report C-14 results from Lake Suigetsu, Japan (35 degrees 35'N, 135 degrees 53'E), which provide a comprehensive record of terrestrial radiocarbon to the present limit of the C-14 method. The time scale we present in this work allows direct comparison of Lake Suigetsu paleoclimatic data with other terrestrial climatic records and gives information on the connection between global atmospheric and regional marine radiocarbon levels.