(CNN) -- British explorer Ed Stafford finished his two-year, 4,000-mile trek along the Amazon River on Monday, completing a feat never before accomplished, his publicist said.
The hike, which he started at Camana, Peru, on April 2, 2008, ended Monday at Maruda Beach, Brazil.
Four months after he started, he was joined by Peruvian forestry worker Gadiel "Cho" Sanchez Rivera. Sanchez intended only to guide Stafford for five days through a dangerous area near Satipo, Peru, but stayed to the end of the expedition.
The 859-day journey took Stafford through three countries and a place in his body and soul he never imagined.
"I'm more tired and more elated than I've ever been in my life," Stafford said in a release. "We've lived through some very serious situations and there have been times when we genuinely feared for our lives, but we never ever thought of giving up. The fact that everyone told us it was impossible spurred us on.
"At first it was terrifying but it's changed in our eyes during the expedition and a place that was once mysterious and dangerous to us is now a place where we feel safe. We've never had more relaxed evenings than when we sit in the middle of the jungle alone around the campfire. It's not a scary place for us now; it's beautiful; we've fallen in love with it and it feels like home."
Despite collapsing from exhaustion on a roadside Sunday morning, Stafford had been confident he would finish in time Monday to catch a scheduled flight home to Leicestershire, England.
"Feeling much better," he wrote in a blog post from northeastern Brazil on Sunday, after catching three hours of sleep. "... will walk all night from now to complete the remaining 85 kilometres."
It's the kind of fortitude that Stafford has summoned time and again since setting out from the Amazon's River source to raise international attention about rain-forest destruction and to help raise funds to combat it.
Along the epic trek, the two men encountered pit vipers, electric eels, anaconda, mosquitoes and scorpions, but very few doubts about whether they'd reach the Atlantic.
"After grabbing something to eat, and replying to emails I finally got my head down at 1:27am," Stafford wrote in a piece for CNN.com last week, after hiking for 15 straight hours. "We've never walked 55km in a day before so we are satisfied with what we've achieved, if a little stiff."
Stafford's mother, Barbara, said Monday she did not spend "an awful lot" of time worrying about her son.
"I only got hear about the bad stuff that had happened only after it had happened," she told CNN. "I can't say there was ever a second when I thought he wouldn't make it unless something dire happened."
Stafford, a former British army captain, and his hiking buddy have seen their share of setbacks. Stafford contracted cutaneous leishmaniasis, a skin disease, and had to have a botfly removed from his skull. Sanchez suffered a nasty machete cut.
But their biggest challenges were far less dramatic.
"Although everyone would like me to say that the hardest thing has been our encounters with (indigenous residents) pointing bows and arrows at our chest, for me that wasn't the hardest part," Stafford told CNN last month. "The adrenalin kicks in and you deal with exciting, potentially dangerous moments like that easily."
"It's been the mundane that had really challenged me," he said. "The weight of the rucksack, the basic food, the constant mosquito bites, the constant thorns. The little things that in a two-day expedition wouldn't bother you have been the things that have actually been challenging."
The greatest pleasures of the journey, Stafford said, have been the warmth of the Brazilian people, with village children frequently welcoming him and Sanchez to new towns and their parents offering home-cooked meals.
Having never visited the Amazon before starting his expedition, Stafford says his quest to save the region won't end with his hike.
"I'm committed now to this place for the rest of my life," he wrote on CNN.com this month, "and I intend to take 'Walking the Amazon' around the world and keep alive the stories of the people we've met along the way, the lives in the Amazon and the tale of the jungle."
Though he says that deforestation means the Amazon "is changing faster than many of us can comprehend," Stafford has also found reasons to be hopeful about its survival while hiking.
"Although (deforestation) is still going on in the moment," he told CNN, "there's a generation coming through Brazil that are very aware of environmental issues and really do care about the Amazon."
As he closed in on the Amazon's mouth, Stafford found time to nurse less lofty desires. He said the first thing he'll do after touching down in England is grab a pint of beer.
And his Peruvian partner, he says, can't wait for a pint of fresh milk.
Back in England, Stafford's mother told CNN she will fix him a favorite meal when he gets back -- shepherd's pie.