JG Development was founded in 1990 by Jeff Grundahl, and his wife Mary Grundahl joined as co-owner in 2005. Still majority owners, the Grundahls began the process of transitioning the company to employee ownership in 2018.

Jeff and Mary are long-time residents of Mount Horeb, Wisconsin. Together, their goal is continued growth of JG Development and its four divisions, and the industries and communities they impact.

In her role as Owner and Integrator, Mary leads the management team and business plan and guides a mission driven culture, drawing on a professional background in sales, marketing and strategic growth planning. She is also a philanthropist and lends leadership to initiatives and organizations focused on economic development, trade education and health. Mary is a Past President of the Mount Horeb Area Chamber of Commerce and a recipient of its George Sievers Award for community service.

Jeff focuses on the future of the company in his role as Owner and Visionary, exploring opportunities for innovation and growth. He has more than 30 years of experience in residential and commercial new construction and remodeling and has served the National Association of the Remodeling Industry (NARI) of Madison, Construction Resource Network and various economic development efforts. Jeff is a NARI of Madison Lifetime Achievement Award recipient. He is also the co-founder and co-owner of development company TRI Holdings.

Jeff and Mary are proud to lead a team of nearly 50 professionals who operate from the company’s offices in downtown Madison and Blue Mounds, Wisconsin.