Bessie Heard dedicated years of her life to philanthropic efforts throughout the McKinney area, helping plant hackberry trees along downtown streets and establishing an American Red Cross chapter during World War I. However, she accomplished her greatest feat in 1967 when the Heard Natural Science Museum & Wildlife Sanctuary opened to the public. With 289 acres of rolling space, the sanctuary functions as a testament to the diversity of local flora and fauna, educating visitors and urging them to protect those species for future generations.

More than 6.5 miles of unpaved hiking trails wind throughout the sanctuary, allowing visitors to immerse themselves in habitats that range from tall-grass prairie to limestone slopes. The grounds shelter more than 150 varieties of wildflowers and plants, as well as more than 240 species of birds, mammals, reptiles and amphibians. In addition to the trails, the sanctuary also features an extensive garden of native trees, grasses, and perennials, as well as a treetop ropes course (reservation required; additional fees apply). Indoors, interactive exhibits and collections impart valuable information on north Texas geology, marine life, and venomous snakes.