Climate/ Geography: This is a picture of the biggest mountain in Mexico. Pico de Orizaba is the tallest mountain in Mexico. Its 18490 inches tall. This mountain started off to be a volcano but then in the winter it’s a mountain. Scientist have tried to figure out the exact height which is 18490.5 inches. The Northern Mexico is bordered by the United States and Southeast is bordered by Brazil and Guatemala. Mexico is 1/5 of the United States. Overall this is the highest mountain in Mexico.