We biked from Koser Park to the Decatur Street Access in Marietta. It's a very well maintained and paved trail. Great condition good enough for skates though we only saw mostly bikers and one skateboarder during our visit. The trail must be relatively new because the donated benches are still in mint condition. There are placards along the trail providing background on various subjects. The trail offers many nice amenities. Among others, Porta-Johns are available at 4 locations and bike repairing stations at 2.
The 6.5 mile trail offers good variety in terms of views and terrains. Though mostly flat and straight, there are short sections that are windy or sloppy. There are open fields and woody areas. The trail is near the Susquehanna River and you can see the water in many sections of the trail which is great. There are even a few spots where you can gain access to the river. We crossed 2-3 small bridges and had a great view of the Shocks Mills Bridge. Around the midpoint is the River Front Park which offers a great view of the river and well maintained picnic area for large groups, and 2 vending machines!
We were surprised to see a sign to Columbia when we reached Decatur Street access, our destination. Per Google Maps the trail ended right there. We asked a couple who just came from that direction and they said the trail doesn't go all the way and riding on public roads would be required to make the connections. So we stuck with our plan and did not continue.
Overall I'm absolutely impressed with how well the trail is maintained, all the amenities it offers, and its vicinity to the river.
UPDATE: Google Maps is not to be trusted! I have since found out the trail continues 3 miles north of Koser Park access, and 4.5 miles south of the Decatur Street access.
From the Decatur Street access, you can continue 2 miles of nice windy trail before having to venture out onto S Bank St in Marietta. At this point you can either cross the railroad and turn right to eventually get to Furnace Rd where the off-road trail resumes, or if you're adventurous, you can continue with the unpaved trail which will end up in the parking lot of the Chickies Rock County Park and when you come out through the tunnel you will end up with the same Furnace Rd connection to the River Trail. This gap is well worth it because the next 1.5 mile towards Columbia is such a delight to ride through. Once in Columbia, you can head back, unless you want to visit the Columbia Crossings Trails Center, in which case, you'll have to ride the sidewalks and cross busy Rt 441 twice. read more