The Harris Hawk is another indigenous species to North America that is in the para-buteo genus. It's most commonly known for it's social behaviors, being one of few birds that consistently will fly in cast and their relatively calm and solid personalities.
One consideration of a Harris Hawk is the climate in which you will be hawking. It's not unheard of for a Harris to contract frostbite during times of cold weather. Their natural climate is relatively warm and arid. It's also a common opinion that their hunting behavior can suffer a little in extreme cold.
Tyler's passage bird taking a solo flight on a rabbit at NAFA, also captured by Patrick Miller
One thing that can't be taken from the Harris Hawk is their impeccable abilities. You may even hear this through "off-color" commentary and calling them "falconry on easy mode". Although it's true the Harris Hawk is an impeccable bird in terms of it's natural skill set, it still takes hard work and effort to make a consistent game hawk.
They are most commonly known for rabbit and jack hawking in the midwest, however they are becoming increasingly popular for squirrel hawking with birds down to the 600g range showing the ability to consistently and safely take squirrels.
To the left is Tyler Sladen with his passage Harris' Hawk flying with other birds at the NAFA 2016 meet as captured by Patrick Miller.
It's also feasible to fly feather with the Harris' hawk from pheasant down to small birds. There are even falconers on the east coast successfully hawking woodcock during their fall migration with Harris' from a perched position. It's also not uncommon for a Harris to take a creek duck when the situation permits a good positioned slip. There is also potential to be conditioned as a glove hawked bird, however, it will normally fall short of the accipiter family in that regards.
Rob Giroux caught this stupendous photo at the NAFA 2016 meet showing the camaraderie often seen with Harris' hawkers. After the catch the falconers will make in and work their own bird after the situation/quarry is assessed.