MILLINOCKET — Roger Poulin, who is deaf and blind, ascended the summit of Mount Katahdin on Tuesday to likely become the first person with both disabilities to finish the entire 2,180-mile Appalachian Trail.

He hiked the rugged footpath, which spans from Georgia to Maine, with the support of Roni Lepore, a support service provider who happens to be deaf herself.

“As a young child, I had so many barriers in my life,” Poulin said, his sign language translated by an interpreter at a celebration in Millinocket on Friday. “People kept telling me I couldn’t do things, and I really took that on. … So I wanted to really let go of that and show people I could do things.”

Now 46-years-old, Poulin, a native of Winthrop, has achieved his dream, one that took him four years of sweat, diligence and some blood to accomplish. When he reached Baxter Peak at the AT’s northern end, he said, it was all worthwhile.

“I wanted to prove to the deaf-blind community that they could do something like this,” said Poulin, who now lives in Washington state. “You don’t have to sit at home all day. You can go out and really adventure.”

Poulin was born with Usher syndrome, a very common condition that affects hearing and vision. He’s deaf, totally blind in his right eye, and has tunnel vision in his left eye. Because of this, he has balance problems and isn’t able to walk steadily.

By completing his journey, Poulin now joins the ranks of legendary hikers such as Bill Irwin, who was the first blind hiker to finish the AT when he reached the summit of Katahdin in 1990. Irwin died earlier this year at age 73.

Poulin’s remarkable journey started in 2007, when he met Lepore at Helen Keller National Center in Long Island. He told her about his dream to hike the AT. By coincidence, she had the same dream, so she agreed to be his SSP — support service provider — to help him along the way.

“The SSP’s role is to guide,” Poulin said. “And so that person can walk ahead of me and come back and let me know if there’s something dangerous ahead or something valuable that I don’t want to miss … if there’s a stick ahead of me at eye level or the mountain’s dropping off.”

The hiking duo set out on April 6, 2010, starting at the AT’s southern terminus, Springer Mountain in Georgia. As is AT tradition, they soon adopted trail names; Poulin became “Adventurous Cane” (Ad-Cane or Cane), and Lepore, proud of her Irish heritage, adopted the name “Rambling Shamrock” (Ramsham for short).

Before setting out, both took courses in backcountry skills and researched the trail tirelessly. Lepore became a certified Wilderness First Aid and Wilderness First Responder.

“I planned to go through the whole thing in six months,” Poulin said. “But once I started hiking, I realized how difficult it was for me. My pace was much slower than other hikers. It was really hard for me to see and I was falling all over the place.”

Lepore usually hiked ahead of Poulin, taking note of hazards on the trail. She has a hearing aid, but she didn’t want to ruin it on the trail, so she left it at home.

On the trail, she communicated with Poulin through American Sign Language, as well as tactile sign language (signing on his hand) and tracking (having him hold her wrist while she signed). She struggled to guide him, while also trying to give him space to experience the trail on his own.

“An SSP makes all the difference,” said Poulin, who hopes his journey raises awareness that SSPs are needed throughout the country to help others the blind-deaf community.

The Appalachian Trail runs through 14 states. That year, the duo hiked from Georgia to Virginia in seven months. Four states down, 10 to go.

“My goal changed a little bit,” said Poulin in regard to his hiking plans. “I wanted to really enjoy the experience and take the opportunities to be off the trail and meet people.”

In 2011, they hiked the Vermont section of trail, as well as a section from where they left off in Virginia to New Jersey. In 2012, they hiked from New Jersey to New Hampshire. And in 2013, they hiked through New Hampshire and Maine.

“It really wasn’t easy,” Poulin said. “I was in a lot of pain every day. But I had a goal in mind. I wanted to quit so many times, but Roni was a great support.”

In Pennsylvania, known by AT hikers as Rocksylvania because of its rocky terrain, Poulin took a fall and struck the crown of his head on a sharp boulder. They washed the gash out with stream water and left the trail to hitch a ride to the nearest hospital, 45 minutes away, where he received four stitches.

“I decided I’d buy a helmet at that point,” Poulin said. “And I wore it for the rest of the adventure.”

Poulin relied on his trekking poles to maintain balance. He also wore safety glasses, protective guards from wrist to elbow, shin guards and fingerless leather gloves.

“It was really funny,” Poulin said. “Other people hiking with us as support people would panic every time I fell, and Roni would just say, ‘Don’t worry. He’s used to the pain. He’ll do his own thing.’”

When Lepore and Poulin came across fellow hikers on the trail, they’d usually just wave.

“At first, people would pass us and think we were cold or unfriendly,” said Lepore, also through an interpreter. “And then we’d arrive at the campsite later and start writing notes back and forth and they’d say, ‘Oh, that’s why you weren’t talking to me.’”

Through writing notes, the two developed friendships throughout their journey and even taught fellow hikers some sign language. By the end, they truly felt part of the AT community.

Both emphasize that they never would have completed the trail without all the support they received along the way from family, friends and, most often, complete strangers.

“Communication makes everything possible, and through a joint effort, we made it through,” Poulin said.

Poulin and Lepore plan to produce a video about their journey in ASL with English captions, and to translate that video into Braille. For them, it’s of primary importance that their story is shared with the deaf-blind community first and foremost.

In 2013, after Poulin had a pine branch surgically removed from his finger (just another price he paid for his dream), the pair hiked through Maine’s 100-Mile Wilderness, a section of trail that doesn’t cross a major road from Monson to Baxter State Park.

On that famous stretch, there aren’t any resupply stores or hostels. They made it through with the help of a new acquaintance, David Whitney, a registered Maine Guide from Sebec.

All they had left was Katahdin — the mile-high monster that all northbound hikers tackle at the end of their AT journey. But things didn’t work out as planned. Just 2 miles from the top, they were forced to turn around. At the end of September, they were losing daylight fast.

“It was really hard to accept,” Poulin said. “I was pretty mad. I had to learn to let go and say to the mountain, ‘See you later.’”

He descended Katahdin with tears in his eyes, determined to return someday and reach the top.

So he did. This June, with support of family and friends, the blind-deaf hiker duo returned to Baxter State Park to complete the final leg of their adventure.

The rainy hike took them 14 hours.

“It was really a brutal hike,” Poulin said. “The rocks were so slippery and a lot of the rocks on the trail were loose. It caused me to stumble and slip, and a lot of the time, I’d end up on my rear end, honestly. I can feel there are bruises back there, but I can’t see them.”

“When we got to the top and saw the Katahdin sign, I had chills,” Lepore said.

“There were so many times I wanted to quit, but I persevered, Poulin said. “So that moment at the top was really overwhelmingly emotional.”

“There had been so many challenges, ups and downs,” Lepore said. “I thought, ‘Are we really done? We got to the end of the AT?’ But really, it’s kind of the beginning of the journey of sharing this deaf-blind dream, that no matter what barriers or difficulties you experience that you should keep going.”

Poulin, for his part, summed his sojourn succinctly.

“Don’t just sit back and let life pass you by,” he said.

Read about the journey on their blog, atdeafblinddream.wordpress.com.