Rick Marks is a man on a mission.
The father of two was diagnosed with the fast-progressing ALS disease, also known as Lou Gehrig’s disease, in October 2016 — and with assistance from close friends and his loving wife Eileen Marks, Rick is taking a leave of absence from his job at Bank of America in Boston to hike 600 miles of the Appalachian Trail.
“It’s definitely ambitious!” Eileen tells PEOPLE of her husband, who has been a hiker for many years. “But it’s what he wants to do, and he’s the strongest person I know.
“We have so much confidence in him, there’s no doubt he will succeed in making a difference.”
Rick, who has severely weakened neck muscles due to ALS and can no longer speak (he uses a text-to-speech app to communicate), is being accompanied by different friends and family members during his ambitious trek. Eileen is tracking his progress closely and will deliver supplies as needed.
On Saturday, he set out from Mount Greylock, the highest natural point in Massachusetts, with his close friend, Ted Kellogg.
If they accomplish the hike, Rick will end up at Maine’s Mount Katahdin.
On Thursday, Rick and his Ted updated their blog with news from the trail.
“The weather is turning cold tonight (51 degrees gets chilly after a few hours outside) so we’re going to test my Boy Scout fire building skills,” writes Ted. “If you see a fire picture over the next few days you’ll know it worked. If not, don’t tell the Boy Scouts!”
Check back on PEOPLE.com as we follow Rick on his incredible journey.