The Route of the Hiawatha is a 15 mile trail in the Bitterroot Mountains. Most of the trail is in Idaho but a portion is in Montana. It is well known for its 9 tunnels and 7 steel trestles. The first tunnel at the top of the trail is known as the Taft Tunnel and is 1.6 miles long. It is cool, wet and dark. You will need lights. Rental lights are only about 250 lumens, not very bright. If you choose to bring your own brighter light be very careful to not blind any riders riding in the opposite direction.
I rode the trail in September 2021. I used a bike rented from the ski area operators. The rental included a light for the tunnels. I also had a second light for the handlebars plus one for my helmet. The surface is packed dirt. It is very dusty, more than most trails. The rental bike was caked with dust making the shifting difficult. This is not a serious issue since the downhill incline is fairly consistent. It does become very important if you intend to ride back up. Be sure your bike shifts before you start down the trail.
An experienced rider that has ridden in tunnels will find the ride fun. If you have never ridden in the dark or in a tunnel you may be a bit stressed at first. After the first tunnel, the remaining tunnels are shorter and not so dark. The views from the trestles are awesome. The Kelly Creek trestle is 850 feet long and 230 feet high. Spectacular scenery means a bucket list worth experience that you will remember for many years. This is certainly a destination trail. It is included in Rails to Trails Hall of Fame.
There are several things to know if you would like to ride this trail. The trail is operated by the Lookout Pass Ski Area. It is also operated much like a ski area. You need a pass to ride on the trail. Only the east end of the trail is accessible. This entire trail is downhill to the end where a shuttle is available to return you to the top, for a fee. The drop off for the return shuttle is below the first tunnel so you will need to ride the long tunnel again to get back to your starting point. They offer equipment rental, bikes and lights, for a fee. Operating season is limited and generally runs from late May to late September but may be adjusted due to snow or other weather conditions. Hours of operation are limited. They sweep the trail (check for people) at the end of each day.
Make note that the trail spans two time zones. Be sure to note the time zone for hours of operation and other time considerations.
Watch a video of my ride through the first tunnel, the 1.6 mile Taft Tunnel on my YouTube channel: Mark's Bike Tock
Here is more of the ride: Mark's Bike Tock