Dennis Louis Costa, 82, of Eureka, passed away on March 27, 2026; just nine months and one day after the passing of his beloved wife, Gina. He was a devoted husband, father, grandfather, great-grandfather, teacher, entrepreneur and friend, and his presence will be deeply missed by all who knew him.

Born in Eureka, Dennis was raised on his family’s ranch in Loleta. Though he was an only child, he was never without family. The Costa family was large and close-knit, and Dennis grew up surrounded by cousins who were more like brothers and sisters. His family was always gathering in each other’s homes, between Blue Lake and then to Fieldbrook, full with a steady rhythm of Sunday dinners, celebrations and gatherings that brought everyone together. These moments were a way of life, shaping in Dennis a deep appreciation for family, connection and tradition that stayed with him throughout his life.

Dennis attended Fortuna High School, graduating in 1961, where he excelled as a student-athlete, playing both baseball and basketball. It was during these years he began dating the love of his life, Gina. After graduating, Dennis moved to San Francisco to attend USF, where he earned his degree in Business Administration. Gina joined him there, and their relationship continued to grow as they built the foundation for a life together.

A chance conversation at a barbecue in Fortuna changed the course of his life. When asked if he would consider returning home to teach, Dennis said yes, and shortly after received a call offering him a position at South Fork High School. That moment marked the beginning of a remarkable 34-year career in education.

Dennis and Gina were married Feb 4, 1967, and had returned to reside in Fortuna to begin their life together. They quickly started a family, welcoming their first child less than a year later. Together, they built a life rooted in love, faith, hard work and community.

Over his 34-year teaching career, Dennis taught business math, economics, typing and coached wrestling. Starting with an emergency credential, he quickly earned his full credential and later completed his master’s degree, at what was then called Humboldt College. He taught at South Fork High School, Fortuna High School, College of the Redwoods evening program, and ultimately finished his career at East High Continuation School, where he found some of his most meaningful and rewarding years.

Dennis was more than a teacher; he was an advocate and a trailblazer. He pushed for change, including advocating for female students to be allowed to wear pants, leading the Interact Club and standing up for teacher rights. It would be difficult to find a student whose life he did not impact in a positive way.

Alongside his teaching career, Dennis had a strong entrepreneurial spirit. He and Gina first ventured into business with “The Playroom,” a bar in Fortuna that served beer and wine. Dennis took pride in being, at the time, the only teacher in California with a beer and wine license, something that raised a few eyebrows but gave him plenty of stories to tell. He especially loved the year the senior class unknowingly chose the outside of the bar as the backdrop for their yearbook photo.

In 1983, Dennis purchased Red Diamond Distributing, growing it from a small operation with two vans into a thriving business with five delivery trucks covering territory from Crescent City to Garberville. After that, in the early 1990s, he launched Costa Distributors, which evolved from home milk delivery into a well-known supplier to local coffee shops, bakeries and restaurants. Through it all, Gina was by his side, managing the books and serving as his partner in every sense of the word.

After Gina’s passing, Dennis poured himself into his work and the relationships he had built, with no intention of slowing down. His dedication never wavered, so much so that even in the ICU, he was focused on his customers and business, coordinating orders and deliveries. His commitment to service and connection was apparent to the very end.

Dennis was deeply proud of his Portuguese heritage and spent years volunteering at the Portuguese celebrations in Ferndale. He and Gina were devoted members of the Catholic Church and dedicated their time to mentoring young couples through the Marriage Encounter program, offering guidance rooted in their own lifelong partnership.

He was also an avid sports fan, with a special love for the San Francisco Giants, as well as the 49ers and Golden State Warriors. Whether in the stands or at home, Dennis could always be found passionately “coaching” from afar, also known as yelling at the TV.

Despite his many commitments, Dennis always made time for his family. Summers were sacred, filled with sunshine and time together that evolved over the years from tents to trailers to a beloved summer home in Willow Creek. These moments created lasting memories that his family will cherish forever.

Dennis lived a life that was never about himself, it was always about others. He gave selflessly to his family, his students, his customers and his community. He wanted the best for everyone around him and worked tirelessly to help them achieve it.

He is survived by his children: Paul (Tammy) of Rocklin, with granddaughters Emily and Kate; Mark (Felicia) of Eureka, with grandchildren Alexa, Nathan, Tawnya and Morgan, and great-granddaughter Violet; Alan (Jaime) of Vista, with grandchildren Nico and Claire; and Stephanie (Scott) Phelps of Eureka, with granddaughter Caitlin. He was preceded in death by his parents, Louis and Virginia Costa, and his wife of 58 years, Gina.

Dennis and Gina shared a lifetime together, they grew up in the same neighborhood, built their lives side by side, raised a family and supported one another in everything they did. After only nine months and one day apart, they are together again.

Please join us for a Memorial Mass, held on Saturday, May 2 at 1 p.m. at St. Bernard’s Catholic Church in Eureka. There will be a reception immediately following in the Parish Hall behind St. Bernard’s Catholic Church, from approximately 2:30-4:30 p.m.

In lieu of flowers, donations may be made to our local Food for People or to Cal Poly Humboldt Girls Basketball Program.