Pennsylvania State Police identified the couple Wednesday night as Jane and Ian McNeill of Doylestown.
The crash occurred shortly before 7 p.m. on Route 202 near Sugan Road in Solebury Township.
Police say a Nissan SUV and a Volvo station wagon collided head-on.
The McNeill's, occupants of the Volvo, died at the scene.
A medivac crew airlifted the man driving the Nissan to a trauma center.
Miles Arnott, Executive Director of the Bowman's Hill Wildflower Preserve, released the following statement on Wednesday:
It is with a very heavy heart that I share the news that Jane and Ian McNeill were killed last night in a tragic car accident on route 202 in Solebury Township.
Jane and Ian were both active volunteers generously giving their time and energy to the community they loved. Jane was deeply involved at Bowman's Hill Wildflower Preserve as a Gala Committee member, Sponsorship Chair, Auction Chair, and served spectacularly as the overall Gala Chair during the Gala's 4th year. Ian was a long-time Board member, served as Treasurer, was a key member of the Marketing, Property, Planning and Finance Committees, and was the current Chair of the Plant Sale Committee. Most recently, Ian focused his volunteer efforts in the Preserve's native plant nursery helping to construct a new greenhouse and sales plan as part of his vision to keep the Preserve growing and energetic. It is difficult to overstate the impact these two amazing volunteers had on the direction and daily operation of the Preserve.
In addition to their tireless work on behalf of the Preserve they both volunteered for many other non-profit organizations including Trinity Episcopal Church in Solebury Township, the Phillips Mill Community Association Art Exhibition, and the Bucks County Audubon Society at Honey Hollow.
Jane and Ian both embodied the true spirit of volunteerism - giving selflessly to make the world a better place. We will miss them dearly.
Our thoughts and prayers are with their family, and we hold them in the light during this heartbreakingly difficult time.
Police are asking any witnesses of the crash to call them, as they try to figure out what happened.