Less than 2 percent of national park visitors are African American. Johnson hoped that if there was anyone who could change that - it would have to be Oprah Winfrey.
She surprised him in a big way early this month when she pulled up hauling a pop up trailer alongside her best friend Gayle King.
"To get her attention to not only respond to me, she's responding to what I'm saying. She's seeing that here we are in one of the most beautiful places in the world and a chunk of our population does not visit places like this and it's a problem," said Johnson. "It's a problem in the sense that all Americans own the national park, but not all Americans are here. And she heard that and wanted to do something."
Park ranger Scott Gediman helped plan the trip and chose a campsite for Oprah nestled next to the Merced River with breathtaking views.
"I've got to be honest - I said, 'I want them to be in this campsite and look up and see Half Dome and North Dome," he said. "We knew they were only going to be here for one night, so it was packing everything in in one night."
Park rangers wanted Oprah to have an authentic camping experience so she cooked for herself, built a campfire on her own, mingled with other campers nearby and even paid for her campsite and park entrance fee.
Even when the cameras weren't rolling, rangers were impressed with how Oprah immersed herself in the experience.
"During some of the off time they had a trivia book about national parks and so they were quizzing each other on parks and they were playing music and just having a good time," said Gediman.
Four weeks later, the famous visitor to the Lower Pines Campground was still the buzz around camp. Ryan Nabors from Carlsbad had no idea who graced his campsite until another camper filled him in.
"A lady was walking by this mornig and was like did you know that Oprah stayed here at campsite 63," he said.
Rangers hope the exposure the park gets from Oprah's show will continue to drive tourism in the future.