Justine Gandolfo was born and raised in Sonoma County. She began English riding instruction at the age of six at Oakridge Training Stables in Santa Rosa; shortly after, Justine's Grandmother bought a training facility and Justine had the good fortune of being raised with access to the many trainers that worked out of the family's business.

As a young girl, Justine trained with Mary Dowdall & Emily Pond for several years showing hunter/jumpers and riding primarily Thoroughbreds, and during this time she competed regularly and was consistently in the ribbons. She also had the opportunity during that time to work with Olympic judge and course designer, Martin Cohen, and attended clinics conducted by George Morris.

Justine spent every spare minute working with horses, often volunteering to ride "problem horses" that the owners where fearful of, and fitting up horses who's owners didn’t have the time. As a result, Justine gained a wide range of experience working with many different breeds and types of horses.

Later on she became interested in western riding, and reining in particular, while watching Art Grunig who worked out of her family's facility for a number of years. It was shortly after that, through a twist of fate, that Justine came to possess her first Quarter Horse. It was at this point that she became truly intrigued with the trainability of the American Quarter Horse.

In 2003 Justine began working with Dianne Sommerfeld who recognized her talent and ability. Under Dianne's tutelage, she is now focusing on Reining and Reined Cowhorse events although she continues to ride a limited number of English horses. Near the end of 2003, Justine and Dianne formed 3D Performance Horses.

Justine excels in colt starting and "problem horses". Her calm demeanor aids her in working with sensitive, high strung and worried horses. This is balanced by an equal talent for working with so called "hard cases". She is an excellent communicator with a special ability to impart her knowledge to others. She is also excellent with fearful riders and with helping to build their confidence.