VERNONIA, Ore. -- There’s a state of mind known to long-distance hikers best described, I suppose, as “autopilot.”It’s the moment when walking becomes so fluid you only consider the surrounding forest -- trees and breeze and birds -- and are barely conscious of moving legs.You just go.This zenlike state is easiest to achieve while hiking because there isn’t much to worry about, as opposed to kayaking (look out for that rapid!), skiing (look out for that turn!) and especially biking (look out for that car!).But every rule has its exception. And for cyclists, the best example might be the car-free bliss of the Banks-Vernonia State Trail.Oregon’s first rails-to-trail system follows an old railroad bed through prairie and the Coast Range on a pathway so smooth it’s easy to slip into an autopilot state where peddling becomes afterthought.This isn’t to say riding the entire trail’s 42 miles out-and-back is easy -- especially for a duffing rider like me -- but with an early start and midway meal, the trail’s forest, creeks and birds create two-wheeled tranquility.“The fantastic thing about this trail is the way it breaks away from the road and heads up into the Coast Range and really stays there the entire way,” said Doug Hopper, who lives in Hillsboro and rides the trail once a month. “There’s no traffic, and being up in the hills and woods is awesome.”A bit of historyThe Banks-Vernonia State Trail didn’t come about by accident.Beginning in the 1920s, trains hauled logs and lumber over this route from the Oregon-American mill in Vernonia to Portland.Business kicked into high gear following the cataclysmic forest fires of the Tillamook Burn in 1933 -- and the salvage logging boom that followed -- but by 1957, the mill shut down. The line was abandoned in 1973.A second act for the railroad began in 1990 when 21 miles was transferred to the Oregon Parks and Recreation Department. The route was paved, following the national rails-to-trails movement, and opened to bikers, hikers and horseback riders in 2010.The route has six trailheads spaced at different points, offering the chance to hike or bike shorter or longer segments. The lack of cars appeals to parents and children, but the trail also is long enough to offer a good workout.On the trailFor those looking to ride the entire Banks-Vernonia State Trail, a choice must be made before you leave the driveway.A one-way ride on the trail is a moderate 21 miles -- but requires a shuttle -- while an out-and-back trek is a more challenging 42.I decided to give the 42-mile option a whirl, mainly because driving two cars more than an hour from Salem to Banks seems excessive.My starting point was Banks Trailhead (elevation 214 feet). Not only is it the closest to Salem, but it also makes the second leg downhill with the Vernonia Trailhead at a higher elevation (628 feet).A nice element of the trail is it’s open year-round except during the worst storms. The riders I spoke with said they enjoyed the trail most during the off-season because of less traffic from hikers/walkers/joggers.It’s particularly beautiful in late autumn, one rider said, when the leaves hit their peak.The first 4 miles from Banks Trailhead are flat as a pancake through a prairie and farmland setting with noise from Highway 26 still within earshot.After passing Manning Trailhead, the trail heads uphill into the wooded Coast Range hills.For the next 7.5 miles, you climb gradually, gaining about 800 feet, a grade that’s not difficult and allows plenty of time to enjoy a forest that isn’t old-growth but still has that fresh smell, deep green and splashing creeks typical of the Coast Range.What most people remember about Banks-Vernonia is the Buxton trestle -- a bridge straight out of the silent movie era. Rising 80 feet high on wooden planks, the refurbished trestle curves around a long corner, carrying riders above the treetops for more than 700 feet.The ride cuts through Stub Stewart State Park for much of its journey, and if you take your time, there are many trails branching off best explored on foot.After a gradual and unrelenting climb, the trail reaches its high point at mile 11.2. If you’re starting to feel tired, take heart because the final 10 miles drop away quickly on the downhill section that ends at Anderson Park in Vernonia.