Convert 30 miles into feet.

Step 1 ：We know that 1 mile is equal to 5280 feet.

Step 2 ：So, to find the feet in 30 miles, we multiply the number of miles by the conversion factor from miles to feet.

Step 3 ：\(30 \text{ miles} \times 5280 \text{ feet/mile} = 158400 \text{ feet}\)