When Tyler Johnstone saw the word "mosque" scrawled on the side of a Parks Canada outhouse in Jasper National Park, he had to turn around.

The Edmonton man pulled over and spent a few minutes covering the anti-Muslim message.

"That wasn't graffiti. It was just hate," Johnstone said in an interview with CBC Radio's Edmonton AM.

"It was a shock to see."

Johnstone, who works for an Edmonton laundry company, was driving home on Highway 16 Wednesday morning when he noticed the bright yellow slur on the side of a roadside washroom.

'I had that sick feeling'

Initially, he kept driving, but a feeling of nausea made him turn around.

"I drove for a few minutes and I had that sick feeling, like you've lied to your mother," Johnstone said.

"Just the feeling I got from it. I don't think anything like that needs to be painted anywhere."

Unable to scrape the paint off without further damaging the building, Johnstone took a roll of vent tape out of his work truck and concealed the hateful message, before calling Parks Canada.

He also shot an emotionally-charged video on his phone to share his disgust with those responsible. As of Friday morning, it had been viewed more than 23,000 times, and had garnered hundreds of messages of support.

"I think it's wrong. It's so wrong," Johnstone said in the video. "It's just disgusting.

'You should be disgraced'

"Whoever wrote that, you should be disgraced. You deserve to be in the bottom of that toilet … and I'm not going to let your stupidity be seen by anybody driving by.

"All this beauty, all this beauty around, and that's what you decide to do? You are a waste of time."

In a statement, Parks Canada officials said similar messages were found on the walls of two other public toilets within the park, and the sites are being repaired.

For Johnstone, he hopes others will remember that even the small acts of kindness can have an impact.

"To me, it's a small act. It really, really is. But we're all kind of small in this world and it's these kind of things that will make a difference," he said.

"It has to start somewhere."