Meet Our Staff
Mark Keith - President, CEO
Email: mark@horizoninc.net
"I believe the success of business and life is to live by the promise; "Seek ye first the kingdom of God, and all these things shall be added unto you"
Mark grew up in Beaufort, SC, and was trained to be a third generation plumber with roots stretching back to his grandfather, who ran a service repair business in Pittsburgh. Mark worked his way through college at the University of South Carolina where he earned a Bachelor's of Science in Accounting. He worked as a field auditor for Ernst & Young upon graduation and then went on to become a Controller for a large, hazardous transportation company. In the early 90's, Mark's entrepreneurial spirit began to take over and he decided to combine his knowledge of plumbing and his experience in finance into a company with an ever-expanding vision for success. Through hard work and good stewardship, Horizon Inc. has become a major player in the national Multi-family industry. Mark continues to guide the company into new and larger markets and has plans to add an electrical division to the already thriving plumbing and HVAC company. He is a very hands-on owner and takes an active role in the monitoring of Horizon's projects.
Mark is the father of three adult children and resides with his wife, Gina, in Bluffton, SC. He is an avid golfer and enjoys sports from both the sideline and the court. He is an active church member but also loves to travel whenever possible.
Gina Keith - Vice President, COO
Email: gina@horizoninc.net
"I don't believe in limitations- personal or business. You can achieve anything if you are willing to work hard enough."
Gina was born in England on a U.S. Air Force base where her father was stationed. After her father retired in the early 1970's, she and her family moved to S.C. As a young child, she worked in the family's furniture business until she graduated from the University of South Carolina. Having bought and sold her first business venture at the age of 10, Gina has always been an entrepreneur at heart. She loves being part of Horizon Inc. and plays a major role in the company's inner dynamics. Gina and Mark have worked side-by-side since the company's inception, juggling the demands of a young family along with a growing business and her career as a high school mathematics teacher. As the company grew larger, Gina retired from teaching and joined Horizon fulltime in 2004 as Chief Operations Officer. Because of her father's background, Gina has a special connection with the Military Privatization housing projects that Horizon helps to build. It brings her real satisfaction to know that she has, in some small part, contributed to the wellbeing of our troops and their families. Along with Mark, she holds the belief that Horizon has only touched the surface of its potential and looks forward to watching the company grow in the future.
Gina feels one of her greatest accomplishments is being the mother of three wonderful children who are still a big part of her everyday life. She enjoys cooking gourmet meals alongside her two daughters and has a passion for art and design. She also volunteers as the head organizer for her church's social functions.
Jim Gresham - Chief Financial Operator
Email: jim@horizoninc.net
"The secret to overhead is – if you are not careful you will be in over your head."
Jim is a Certified Public Accountant who worked for 5 years in public accounting before going into the private sector where he has over 20 years experience serving as CFO for large corporations. Jim is a graduate of the University of North Carolina and resided in Greensboro before relocating to Hilton Head, SC. Jim's dedication and expertise has helped put Horizon in a very strong financial position.
Jim is a caring person who is always ready to lend a hand to those around him. He feels the responsibility to be involved in his community and various civic organizations. Some of his past and present volunteer positions include Chapter Chairman for American Red Cross, Treasurer of UNC Greensboro Alumni Association, Boy Scout Troop Leader, and United Way associate. Jim has a green-thumb and loves spending time with his wife, Cathy, working on landscaping projects. He is also the father of two grown children.
Tim O'Brien - Vice President, Business Development
Email: tim@horizoninc.net
"Short people rock!"
After 15 years in wholesale distribution, Tim joined Horizon in 2007 as the Purchasing Manager at our corporate office. His current responsibilities include developing Horizon's plumbing and HVAC multifamily businesses. Born in Newport, Rhode Island, Tim grew up in a military family and eventually settled in Summerville, SC. Tim is an alumnus of the University of South Carolina and holds a Bachelor's Degree in Business Administration.
Tim and his wife, Adria, have 3 young boys that keep them very busy. When he is not at a baseball park somewhere, he enjoys fishing and boating.
Courtney Keith - Business Development Coordinator
Email: courtney@horizoninc.net
"I'm knot a blonde! I'm knot, I'm knot, I'm knot!"
Courtney is a recent graduate of the University of South Carolina with a B.S. in Business Management. She has worked in the family business for 7 years in varying capacities, learning the nuances that make a successful company. She has been instrumental in the development of Horizon's service department and employee wellness program.
Courtney is the oldest of three children and lives in Bluffton, SC. She enjoys going out on her boat in the summer and snowboarding in the winter months. Courtney has a passion for traveling, cooking, and interior decorating.
Trey Testino - Vice President, HVAC Division
Email: trey@horizoninc.net
"Success is to be measured not so much by the position that one has reached in life as by the obstacles which he has overcome." (Booker T. Washington)
Originally from Augusta, GA, Trey brings 20 years experience to Horizon's heating and air conditioning division. Trey attended Augusta College and holds an A.S in Mechanical Engineering. His knowledge of design and installation of HVAC systems for commercial and residential buildings is unsurpassed in the multi-family arena.
Trey's many interests include music and spending quality time with his wife, Diana, and stepdaughter, Lauren. Trey is also an excellent golfer who enjoys playing as often as his schedule allows.
Slate Williams - Estimating Director
Email: slate@horizoninc.net
"You can't fight the wave cuz." (Big Z, Surf's Up)
With over 10 years of plumbing experience, Slate started with Horizon as a project superintendent and is currently head of the estimating department. After attending Armstrong State College, he started his career in Outside Sales with Hughes Supply, a national plumbing and HVAC supply company. Slate holds Master Plumbing licenses in the states of South Carolina and Oklahoma.
Slate resides in Savannah, GA with his wife, Ann, and their two young children. He is an avid golfer and loves boating on the coastal waters surrounding his home. Slate also enjoys sports of all types, music, watching movies, and taking his family to Disney World.