Officially getting an international border in 1848, this area of land is up to 150 miles wide & has about 2,000 miles of coastline
The Final Jeopardy clue for Monday, November 3 2025 came from The Western Hemisphere category. The clue asked: “Officially getting an international border in 1848, this area of land is up to 150 miles wide & has about 2,000 miles of coastline.” The question pointed toward a distinct landform shaped not only by geography but also by a pivotal treaty in North American history. The correct response connects the result of the Mexican-American War and a peninsula known for its remarkable length, narrow width, and extensive coastline along two major bodies of water.
What is Baja California?
The Baja California Peninsula is the correct response. This narrow stretch of land in northwestern Mexico extends roughly 775 miles south from the U.S. border and is bordered by the Pacific Ocean on one side and the Gulf of California on the other. Its width varies, reaching up to around 150 miles across at its widest points. With about 2,000 miles of combined coastline, it is one of the most recognizable peninsulas in the Western Hemisphere.
The peninsula officially became separated from what is now the U.S. by an international border in 1848 through the Treaty of Guadalupe Hidalgo, which concluded the Mexican-American War. That agreement established the political boundary between the United States and Mexico, running at the peninsula’s northern tip near modern-day Tijuana and Mexicali. The land remained part of Mexico, and the treaty clarified territorial control following years of regional dispute and conflict.
Historical Context and Treaty Significance
The Mexican-American War and the Treaty of Guadalupe Hidalgo shaped the modern border between the United States and Mexico. Before 1848, North America’s western frontier was not fully defined, and control over regions such as Alta California and Baja California had shifted through colonial periods and early nationhood. The treaty altered the map significantly, granting the U.S. vast territories while confirming Mexico’s control over Baja California.
The treaty remains one of the most consequential diplomatic agreements in North American history. It marked not only territorial change but the formal creation of a fixed international boundary at the Baja Peninsula’s northern edge. That border still stands as the dividing line between Mexico’s Baja California state and the U.S. state of California.
Geography and Coastal Features
Baja California’s dramatic geography is central to its identity. Running along two distinct marine environments, the peninsula features diverse coastlines, rugged mountains, desert plains and unique ecosystems. The Pacific side is known for cooler waters and strong wave activity, while the Gulf of California side is calmer and biologically rich, often called “the world’s aquarium” for its marine biodiversity.
The length of the coastline, estimated at roughly 2,000 miles, includes beaches, cliffs and coves that stretch across both Baja California and Baja California Sur, the peninsula’s two Mexican states. The slim landmass, no wider than 150 miles, creates a maritime corridor that has long supported fishing, shipping and tourism industries.
Modern Standing and Cultural Context
Today, the Baja California Peninsula plays a central role in Mexico’s tourism economy, attracting travelers to destinations such as Tijuana, Ensenada, La Paz and Cabo San Lucas. The region blends coastal living, historic towns, and desert landscapes. Its proximity to the U.S. border also contributes to cross-border cultural and economic ties.
The peninsula maintains strategic and environmental importance in the Western Hemisphere. With protected natural areas, marine reserves and research centers, it supports conservation efforts and scientific study, reflecting its ongoing relevance beyond its geopolitical history.
Conclusion
The Baja California Peninsula fit every element of the clue: a major landform in the Western Hemisphere, receiving an internationally recognized border in 1848 and defined by about 2,000 miles of coastline with a narrow width reaching up to roughly 150 miles. The Final Jeopardy focused on both geography and history, highlighting how a prominent piece of land became permanently marked on the political map through a historic treaty.