Let's analyze the annual mean precipitation data provided for each option to determine which area received the most overall precipitation in 2000. We need to find the area falling into the highest ranges of precipitation.
### Step-by-step Analysis:
1. Rocky Mountains: Generally, the Rocky Mountains range can experience a variety of precipitation patterns depending on the elevation and location. However, it usually falls within the middle precipitation brackets, commonly within the 12.01 - 30.00 inches range.
2. Great Plains: The Great Plains is known for having relatively low precipitation compared to mountainous regions. It most commonly falls within the lower to middle ranges, typically between 5.01 - 20.00 inches annually.
3. Sierra Nevada Mountains: This area is known for receiving significantly high amounts of precipitation, particularly in the form of snow during the winter months. This region frequently records precipitation in the highest brackets, often exceeding 70.01 inches and potentially going over 100.00 inches annually.
4. Atlantic Coast: The Atlantic coast can have varied precipitation levels, often falling in the middle to higher range depending on the specific location along the coast. Typically, annual precipitation ranges from around 30.01 to 50.00 inches.
### Conclusion:
Taking into account the precipitation categories and understanding the geographic and climatic conditions of each area:
- The Sierra Nevada Mountains generally stands out for recording the highest amounts of precipitation, often exceeding the highest categories listed in the problem.
Thus, the area of the United States that received the most overall precipitation in 2000 is:
Option C: Sierra Nevada Mountains
