Final answer:
Gifford Pinchot was the first Chief of the US Forest Service, where he played a significant role in conservation, particularly in sustainable natural resource management and anti-clear-cutting policies.
Step-by-step explanation:
Gifford Pinchot's primary role in federal conservation work was as the first Chief of the US Forest Service, not as a Cabinet Secretary. In this capacity, he focused on scientifically managing government lands to ensure the sustainable use of natural resources.
Under the guidance of President Theodore Roosevelt, Pinchot was influential in implementing policies aimed at preserving natural resources for the public benefit. He vigorously promoted the idea that the government should act to prevent the destruction of forests, and he was key in increasing the number of protected forests, mandating reforestation efforts by lumber companies, and banning the practice of clear-cutting entire forests.
His leadership in the Forestry Service symbolized the utilitarian conservation pillar of the early conservation movement, and thus he is often remembered for his significant role in environmental conservation during the Progressive Era.