To find the total number of acres in the national park and the national forest combined, you need to add their areas together.
The area of the national park is \( 1.42 \times 10^6 \) acres, and the area of the national forest is \( 1.2 \times 10^6 \) acres.
Adding these together:
\[ 1.42 \times 10^6 + 1.2 \times 10^6 = (1.42 + 1.2) \times 10^6 = 2.62 \times 10^6 \]
Therefore, the total area of the park and forest combined is \( 2.62 \times 10^6 \) acres.
The correct response is: 2.62×10^6 (2.62 times 10 superscript 6 baseline).