The Newfoundland section of the IAT begins at Port aux Basques on the southwest coast, not far from the Newfoundland to Nova Scotia ferry terminal. From there the IATNL long-distance - or thru-hiker's - route extends north along the Long Range Mountains of the island's west coast to Crow Head, just east of L'Anse aux Meadows on the Strait of Belle Isle. The route is composed of the Trans Canada Trail, an assortment of logging and secondary roads, and IATNL-developed wilderness mountain trails. These 1 to 4-day trails and trail routes are spread throughout Western Newfoundland, from the Grand Codroy Way in the Codroy Valley, the Lewis Hills and Blow-Me-Down Trails between Stephenville and Corner Brook, the Overfalls Trail at the southern end of Gros Morne National Park, the Devil's Bite and Indian Lookout Trails between Parsons Pond and Portland Creek, and the French Shore Trail on the Atlantic coast between Conche and Croque.
After leaving Port aux Basques, the IATNL long-distance route follows the Newfoundland Trailway/Trans Canada Trail for 160km (96miles) to Stephenville Crossing where it connects to the 5km (3mile) Indian Range Trail to Noel's Pond, 4km (2.5miles) east of Stephenville.
From there the route enters Cold Brook Road and follows backcountry logging roads for 50km (30miles) until it reconnects to the Newfoundland Trailway 15km (9miles) south of Mount Moriah in the beautiful Bay of Islands. Along the way it passes the southern trailhead for the Lewis Hills Trail, where hikers can cross the Fox Island River and climb spectacular mountains of peridotite to Cabox, the highest point on the island of Newfoundland.
At Mount Moriah the trail route follows the paved road to Corner Brook before continuing to the Humber Valley Trail on the north side of the Humber River. This trail extends 25km (15miles) along the scenic river valley to Humber Valley Resort before connecting to Goose Arm logging road. Hikers then have the choice between following the road to Deer Lake before heading north to Wiltondale at the entrance to Gros Morne National Park, or following an intersecting logging road to Glenburnie in the South Arm of Bonne Bay.
From Wiltondale the east branch of the IATNL follows Route 430, the Viking Trail, 28km (17miles) to Gros Morne Mountain. At Gros Morne hikers can follow the Park's Long Range and North Rim Traverses across the backcountry and return to Route 430 just south of the community of St. Paul's. (Contact the park for information and permit.)
From Glenburnie the west branch of the IATNL follows Route 431 8km (5miles) to Woody Point. There hikers must take a pedestrian ferry across Bonne Bay to the town of Norris Point, before following the highway to Gros Morne mountain and the Long Range Traverse, or to St. Paul's.
At St. Paul's the IATNL continues allow Route 430 to Cow Head, where it detours into town and Shallow Bay campground. From the campground the IATNL continues on Route 430 to Five Mile Road, approximately five miles north of Parsons Pond, five miles south of Portland Creek, and five miles west of the Flat Hills. At the Flat Hills hikers can follow the IATNL's first official trail, the Indian Lookout Trail, on a scenic 40km loop around Southwest Feeder Gulch.
From Five Mile Road the IATNL continues on Route 430 another 20km (12miles) to Zinc Mine Road, 3km (2miles) north of Daniel's Harbour. Five kilometers (3miles) along this road the trail route turns north onto a backcountry logging road with views of the mountains for 50km (30miles) until returning to Route 430 at Hawkes Bay.
The IATNL continues on Route 430 for another 7km (4miles) to the Port Saunders/Port au Choix intersection. There the route makes a 25km (15mile) looping detour into those towns and returns to Route 430 3km (2miles) south of Eddies Cove West. From there the IATNL continues on the Viking Trail for another 100km (60miles) to Eddies Cove, where it detours for 40km (24miles) onto the old coastal road through Watts Point Ecological Reserve to Pistolet Bay.
At Route 435 in Pistolet Bay the IATNL continues for 18km (11miles) around the bay until it reconnects with Route 430. After another 7km (4miles) along this highway, the Viking Trail and IATNL turn onto Route 436 and continue for another 23km (14miles) to Spillars Cove where the IATNL takes the 1km Cape Raven Trail to the Crow Head terminus.
Two kilometers beyond Cape Raven Trail hikers can visit the UNESCO World Heritage Site and National Park at L'Anse aux Meadows, the only authenticated Norse (Viking) site in North America.