The paved section, which is from downtown to a mile south of Giant Springs, is scenic and well maintained. Plenty of restrooms, but not much water. Giant Springs is unique, don't miss it. Good parking and modern restrooms at the Lewis & Clark Center at 4201 Giant Springs Road.
The gravel section, which is east (downstream) of Giant Springs, has a lot of hills and so you need a mountain bike.

The paved section through Butte is on about a 3% grade, a little steeper than most rail trails. At Wyoming Street the trail leaves the railroad grade and heads up the mountain another mile or so to the miner's memorial that looks over the Berkley Pit. The mountain section is steep, I had to walk my bike up two of the grades, but the effort was well worth it as the views over Butte area were terrific. There are modern restrooms and picnic area on the mountain section.
The gravel section between the mining museum and rocker is in good shape.

Asphalt trail in excellent condition. New trail access stations at Rocker and Silver Bowe have modern restrooms, drinking fountains, and parking. The Rocker Station at 1208 Grizzly Trail is near the end of the B & P Hill Trail so you can connect to both trails.

If you are riding in Billings don't miss this trail. There is a half mile long hill to get up on a ridge that overlooks the city.

Park at the parking lot at the pioneer cemetery behind Applebee's(204 Main), cross the street and the trail goes up the hill. If you go down the hill you end up at Alkali Creek trail.

This trail is a wide sidewalk along the street that kind of follows Alkali Creek. There are prettier rides in Billings. This trail does connect with the Swords Park Trail.

Good parking at the pioneer cemetery behind Applebee's (204 Main)

Nice paved trail along the river, fairly flat and smooth with nice views. The north couple of miles is on an abandoned railroad grade through neighborhoods. Just south of the bridge over Alkali Creek near the sewer plant is the turnoff to get to Alkali Creek trail and Swords Park Trail. This connection goes under HWY 87(Main Street) but still a couple of blocks riding on the sidewalk.

I parked downtown on main street, then rode to both ends of the paved trails and got 20 miles. That would include a few blocks of riding on residential streets, but impossible to get lost as it is a small town. Trails are flat and smooth. Three Forks has a couple of historic hotels and several restaurants.

Trails are really for walkers, a mountain bike would work. The highway is low traffic, so I just biked the the park on the paved shoulder.

I rode both south and west part way on this trail. On the westerly portion I turned back because the trail runs ride along US Hwy. 2 and the noise was bothering me. The southernly portion also runs along the busy US Hwy 93 but the noise is not so bad. I am just getting back into biking after a two year lay off and this ride was perfect.