Six years ago Vickie Thurber filled a void.

In spite of the numerous horse farms and riding barns dotting the roads and fields of the Island, there was, Ms. Thurber felt, something missing in the equestrian community: therapy riding.

She gathered a board of directors, asking Rebecca Miller and Claire Harrington if they would help with the endeavor, and founded Rising Tide Therapeutic Equestrian Center as a nonprofit organization. And since its inception, the center has dedicated itself to providing lessons to riders with physical and mental challenges. Whether the rider is a nonverbal autistic child, a visually-impaired adult, or a wheelchair-bound teenager, working with the horses allows a freedom not present in the riders’ everyday lives, executive director Risë Terney said in an interview with the Gazette.

A network of physicians and therapists around the Vineyard starts the referral process to set up lessons with instructors Christy Arenburg and Kara Thibodeau, both of whom are certified by the Professional Association of Therapeutic Horsemanship International. The four horses living at the Rising Tide barn are just the right equines for the job, calm and patient, and very appreciative of their regular trail rides. A core group of volunteers donates their time to help with everything from administrative work to barn cleanup to lesson assistance.

But Rising Tide is still “relatively young,” Ms. Terney said, and is currently going through what most nonprofits do eventually: growing pains.

The center has no intentions of going anywhere, Ms. Harrington said, but basic costs of simply providing for the animals who are the core of the programs — hay and feed, blacksmithing, medical expenses — have increased. And Rising Tide has found itself slowly backed into a financial corner.

“We’re charging the fees we feel we can charge and still stay true to our mission,” Ms. Terney said. Fees, however, cover a little less than half of the center’s operating costs. The board remains committed to providing scholarships for many of the riders.

“It’s tough [for people] to make rent; it’s tough to make ends meet,” Ms. Harrington said. “With some of our families, they want the service and they need the service.”

Additionally, Rising Tide hopes to expand its programs in the future to work with a greater range of disabled riders, hire additional full-time support staff and hold longer sessions that encourage more horse-rider interaction, allowing attendees to participate in grooming and tacking — therapeutic activities in their own right.

But first, the organization is working to “get over the hump,” Ms. Harrington said.

“We really are committed to make sure that this program stays, for our families and for the children that we already serve and that we want to serve in the future,” she said.

The center hosts its annual fundraiser in late summer, which will again be held at the James Cagney Estate in Chilmark. This year it takes place on August 8.

Rising Tide Therapeutic Equestrian Center is a 501(c)(3) nonprofit organization. For more information, please contact Risë Terney at (508) 693-1185.