Final answer:
Spain is the country with the Basque region that extends from southwestern France into the north. The Basque Country is known for its distinct culture and language, and it borders the southern regions of France.
Step-by-step explanation:
The country that has the Basques stretching from southwestern France into the north is Spain. The Basque Country (Euskadi in Basque language) is an autonomous region in northern Spain with a unique culture, language, and many traditions distinct from the rest of Spain.
It shares a border with Southern France where the Basque cultural region extends into parts of the French departments of Pyrénées-Atlantiques and Labourd.
The landscapes of France are diverse, with the northern low-lying coastal plains contrasting to the Alpine ranges in the east, showcasing Mont Blanc, the highest mountain in France.
Noteworthy in regard to the question are the Pyrenees, a mountain range forming the natural border between France and Spain. The rough terrain and cultural diversity of the region have served as a backdrop for complex historical relationships between these two countries.