As we mark the 40th anniversary of Earth Day today, it is worth noting that the conservationist movement really began a century ago under the leadership of President Theodore Roosevelt.

It is somewhat ironic that Roosevelt was a Republican – the political party that usually isn’t associated with today’s conservation movement – though he did later break away from the GOP to form the more progressive (and short-lived) Bull Moose Party.    

I’ve been reading about Roosevelt lately in Aida Donald’s book, “Lion in the White House,” sort of as a prep course for tackling a much-larger tome, Douglas Brinkley’s 940-page “The Wilderness Warrior: Theodore Roosevelt and the Crusade for America.” I already knew about T.R.’s love of nature and push for land conservation, but the more I learn about our country’s 26th president – and not just regarding his push for conservation – the more I am impressed by the man who once expressed his fondness for the West African proverb “Speak softly and carry a big stick; you will go far.” (Incidentally, that proverb seems to reflect the Obama Doctrine for the world stage. But I digress …)

During his presidency, Roosevelt protected approximately 230,000,000 acres of public land in the form of five national parks, 18 national monuments, 150 national forests, 51 federal bird reservations and four national game preserves. As someone who enjoys hiking in such places and tries to visit at least one new natural wonder each year, I’m thankful to Roosevelt for what he started.

Roosevelt wasn’t the first president to establish a national park – that honor belongs to Ulysses S. Grant, who made Yellowstone the first one in 1872 – but he was the one who arguably did more for conservation than any other president before or since. Arguing that conservation of natural resources is “vital for the future of the nation,” Roosevelt helped ignite the then-relatively new idea of preserving land into a full-fledged movement.

“We of an older generation can get along with what we have, though with growing hardship,” Roosevelt said in an address to schoolchildren in April 1907. “But in your full manhood and womanhood you will want what nature once so bountifully supplied and man so thoughtlessly destroyed. And because of that want you will reproach us, not for what we have used, but for what we have wasted.”

Think about how different certain things would be if not for the efforts of conservationists. Remember when there were plans to build a development on Plum Island early last decade? I still shudder when I think about how close we came to the Starved Rock experience being forever altered in a bad way.

Now think about how development could have changed other natural wonders of greater scale. Roosevelt did.

“You cannot improve on it,” he once said of the Grand Canyon. “The ages have been at work on it, and man can only mar it.”

That goes for natural wonders both great and small. It is to Roosevelt’s credit that this message is among his lasting legacies – and not only on Earth Day.

This column also appears in today’s edition of Ottawa Delivered.