To find the total area of the national park and the national forest combined, we 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.
Now, let's add these two values:
\[ 1.42 \times 10^6 + 1.2 \times 10^6 = (1.42 + 1.2) \times 10^6 = 2.62 \times 10^6 \]
So, the total area in acres of the park and the forest combined is:
\[ \mathbf{2.62 \times 10^6} \text{ acres} \]
Therefore, the correct response is:
2.62×106 (2.62 times 10 superscript 6 baseline)