It's one of those feel-good Olympic stories that dreams are made of... or so we thought.
When Mark was five the Tewksbury family moved from Calgary to Dallas. They beat the Texas heat by hanging out at the local pool. Five years later, when the family moved back to Calgary, Mark just kept on swimming.
The '76 Summer Games inspired him to race competitively and 12 years later, he won a silver in Seoul. Four year later, in Barcelona, Mark broke the Olympic record for the 100-metre backstroke. Not only did he capture gold, but the hearts of people all over the country.
When he retired from competition Mark started what looked like a promising career with the International Olympic Committee. He was well-known and liked amongst his peers; he was dedicated to the spirit of the games, and was regarded as a natural leader in the Olympic community.
But inside, Mark was drowning.
He was gay. And the IOC, his peers, and even his coaches were discouraging him from coming out.
It took some time, but Mark eventually took a very bold and brave step in 1998 and came out, becoming Canada's first openly gay Olympian. While he lost a few endorsement deals and faced some very real criticism, he also found new meaning in life. He spoke out against IOC corruption, founded the first-ever World Out Games, and became a mentor to athletes who felt stuck in the closet.
Now Mark finds himself back on the Canadian Olympic team, as Canada's Chef De Mission. His role is to provide young Olympians with leadership, support, and inspiration. Now that's the kind of feel-good story Olympic story dreams are made of.