Yesterday, an estimated 40,000 people gathered in Washington D.C. for the Forward On Climate rally.

Some say the numbers exaggerated. Nonetheless, organizers are calling it the largest environmental action in the history of the U.S.

My almost-12-year-old son and I found out Friday that we were going to be part of it.

The purpose of the rally was to demand that President Obama kill the proposed Keystone XL oil sands pipeline (watch the mindblowing video here) and support his promise to, “…respond to the threat of climate change, knowing that failure to do so would betray our children and future generations.”

It took 11 or so hours on a cramped bus to get there (two Sierra Club buses from Chicago transported 200 of us for a mere $100 each). We left Saturday night, arrived Sunday morning and the rally started at noon that same day.

The bone-chilling weather (19 degree wind chill at the start) invigorated me and, I think, everyone else.

I ran in place to keep warm while 350.org founder Bill McKibben and others pumped up the growing sea of people, a memorable kick-off to our march around the mall.

My son and I had the opportunity to whale on an enormous drum that provided the background beat to  the chants that pushed us forward.

Hey, Obama, we don’t want no climate drama!

We hopped back on the bus Sunday night. An hour into the trip, I regretted trading our back-of-the-bus seats with extra leg room for cramped seats with a much desired phone jack. My son slept, head on my shoulder (used intermittently as my pillow), the entire 11-hour ride back.

We arrived back to Chicago Monday morning.

It was one of the longest and shortest trips I’ve taken in my lifetime. It also ranked up there as one of the best. We met some amazing people—including Ellen Gunter, who has written for elephant in the past and made it possible for me to attend the rally—and my commitment to the environmental movement is stronger than ever.

Below are some photos by activist/photographer Jenna Pope (used with her permission), who I connected with today on facebook after my new friend (and soon-to-be elephant contributor) Laura shared one of Jenna’s photos:

Here’s another photo, courtesy our friends at Moms Clean Air Force (MCAF):