There are 2 trailheads to start from The furthest parking lot to the east requires a NP pass or NW pass. We started Iron Goat trail from Martin Creek trailhead on lower grade, up the switchbacks, over to Wellington Trailhead. No passes required there.. You will see a red caboose at the earlier parking area. The switchbacks starting at the caboose are many but that means they are not steep. Once we topped the rail grade we turned east (right). There are descriptive placards along the trail. I loved walking along historic route. We ate wild strawberries along the rail grade trail. Watch out for nettles. The tunnels are closed for safety reasons but the snowsheds are open their full length. There are many sources of water along the trail but nothing difficult to ford. Next time I come back I will follow the loop trail reaching towards the west.