Stephen Queen is being remembered as a passionate environmentalist dedicated to making making the world a better place for his family and future generations.

He fell off a cliff at a hiking lookout at Morialta Conservation Park yesterday afternoon.

“No one can believe it, He was so young, so full of energy,” Katherine Queen told 9News.

Mr Queen had been hiking with a friend when he fell down a steep ravine at Morialta Conservation Park, about 10 kilometres east of Adelaide.

Paramedics rushed to the rescue but he couldn’t be saved

“Dad rang me and he said the police were at the house and there had been a terrible accident,” Ms Queen said.

It’s understood Mr Queen climbed over a barrier near Deep View Lookout to pick up litter – a plastic bottle – but slipped and fell.

“He was passionate about climate, he was passionate about our society, and of course he would be trying to get litter off the ground,” his sister said.

The 34-year-old is being remembered as a loving father, brother and son who could connect with just about anyone.

“He could talk to anyone about anything and he wanted to learn about different cultures. he wanted to learn about different coffees he was so passionate about coffee,” Ms Queen said.

Mr Queen had been looking forward to a bright new chapter in his life as he neared the end of his university degree.

He had hoped to begin a career in environmental science to make a difference in the world.

“I want to make sure he had a lasting impact, because I know he would want that,” his sister said.