His father, Todd Porter, said the 20-year-old enjoyed exploring new surroundings.
"Almost every family vacation, we'd get lost on a hike and he'd love that. Just wandering around and seeing what's there," Todd said.
Zachary was on a trip with friends in Alaska. On Sunday evening, he was walking on the mud flats at the treacherous Turnagain Arm estuary when he got sucked into the silt.
Despite efforts by firefighters and Porter's friends to free him from the mud, the incoming tide submerged him. Porter's family was notified by Lake Bluff police.
"The number of friends that are completely devastated by his death is really a testament to what a big heart he had, and how many people he impacted in his 20 years," said Elizabeth Porter, Zachary's sister.
Elizabeth said Zachary, the youngest of three siblings, just finished his sophomore year at Washington University in St. Louis. She considers him a role model.
"He was the most kind, compassionate, hard-working, smart, driven well-rounded person I know," Elizabeth said.