The 1908 Governors Conference on Conservation, largely financed from Pinchot's personal income, brought conservation fully into public view. Attended by governors, members of Congress and the Cabinet, Supreme Court judges and prominent private citizens, it was the first meeting of its kind to address the problem of protection and management of natural resources. Shortly after, Pinchot was appointed chairman of the National Conservation Committee, whose task was to prepare an inventory of the United States' natural resources. In February 1909, the North American Conservation Conference convened at the forester's suggestion. Plans followed for an international conference to be held at The Hague but was aborted by change in administrations.

Pinchot did not share with President William Howard Taft the personal relationship he had enjoyed with Roosevelt. Taft was not an advocate of conservation. Nor, in Pinchot's view, was the President's new Secretary of the Interior, Richard Ballinger. Ballinger wanted to turn some Alaskan coal lands in the public domain over to private ownership. After a long battle, the indignant Pinchot, through a Senator, attacked both Ballinger and Taft on the floors of Congress. Taft fired him. The public was outraged, which is what Pinchot wanted, and the eventual backlash brought conservation back into the public arena.

The outcry against Pinchot's firing and his continued popularity undoubtedly fueled his thoughts for a political future. He formed and financed the National Conservation Association and served as its president from 1910 to 1925. The organization's two main objectives were to fight the movement to give the national forests over to the states, and to control power development on government property.

When Roosevelt failed to win the Republican presidential nomination from Taft in 1912, Pinchot took an active role in founding the new Progressive Party, commonly known as the Bull Moose Party. The forester represented the more radical wing of the party's politics and made strong statements on the need for stricter antitrust laws and innovative social reforms. In 1914, running on the Progressive platform, Pinchot became a candidate for an elective office for the first time with his bid to win a United States Senate seat in Pennsylvania. He lost.