Agree with both Maurice and Fishidiot above.
I've fished the Upper Delaware River for a long time and the bows and browns seem to thrive side-by-side. Interesting fact is the bows lived there first.
On the D River, the bows tend to populate the mainstem, lower down in the River than the browns in the warmer water. Also, from the anglers standpoint, the bows usually inhabit the faster water, feed more during the day, and fight and jump like there's no tomorrow.
Anyone that has fished out-west knows first hand that both bows and browns inhabit many of the famous and not-so-famous rivers and streams.
Finally, as Fishidiot wrote above.......whatchagunnadoaboutit anyway?