To find the circumference of a circle, you can use the formula:
\[ C = \pi \times d \]
where \( C \) is the circumference and \( d \) is the diameter. Given that the diameter \( d \) is 4.5 miles, and using \( \pi \) as 3.14, we have:
\[ C = 3.14 \times 4.5 \]
Now, let's calculate that:
\[ C = 3.14 \times 4.5 = 14.13 \]
Thus, the circumference of the circle is approximately 14.13 miles when rounded to the hundredths place.