I returned on one of those great Midwestern fall days to complete the portion of the Glacial River Trail south of Jefferson. I found the few miles that were in-fact a former railroad. The rest of the trail is in the WI-26 freeway corridor or on rural roads and city streets, but the trail is all paved.
The city of Fort Atkinson is very attractive with trail amenities including public art. I again found that the TrailLink map was a necessity as the signage on the tail is sparse.
My only negative is there is no need to do the on-highway portion south of N Wright Rd unless you want to continue to the connection to the Spring Brook Trail that will take you into Janesville.
For an out and back trip consider places where you can use the parallel old WI-26 for a different landscape view.

The Glacial River Trail in the Rock River valley is untypical for Wisconsin state trails in that it is entirely paved and not a rail-to-trail. It has a great mix of segments in the WI-26 freeway corridor, city streets and rural roads, with some good grades. I did the north part of the trail from Jefferson to the junction with the Wild Goose State Trail. There are no services provided by the trail owner, but the trail is free to use. The signage for the trail-turns is minimal so the Trail-Link map downloaded on your smart phone is a must. I especially enjoyed my ride thru the river towns of Jefferson, Johnson Creek and Watertown, where I took the time to ride around the downtowns. I will come back someday to do the south portion.

I grabbed the trail north of Janesville on my road bike. Crossed the bridge over the highway and did about a mile on the county road before winding through a new housing development and finding the actual trail. It's in great shape, lots of gentle rolling hills and a couple of roundabouts but not a single person anywhere along the trail. I rode to Milton and most of the trail parallels the highway so it's loud on one side but beautiful and agricultural on the other side. I saw hawks and finches and no humans of any kind. It was pretty sweet. I only gave it 4 stars because of the highway driving . Otherwise it's a 5-star paved trail.

I rode this trail today and was underwhelmed. It is very average. I rode from the south end all the way to the end,and then rode the Rawley Point Trail. On the way back on the Mariner's trail I rode on the same side of the trail that I started on. Why on earth are there so many signs saying "do not enter" on the way back heading south? There is no path on the other side of the road,and it's a 45 MPH road. I would not ride on that road.

Very nice, easy ride with fantastic views of Lake Michigan the whole way.

Perfect for kids and families!

Tied this loop into our Friendship trail ride. The Trestle Bridge was awesome with nice views. The loop offered nice views of the lake. Not nearly as many people using the trail as I had expected for a Saturday. Those that were on the trail were using good trail etiquette.

Started at the Umland Road parking area. First few miles were crushed stone. A few areas required some caution, especially the downhill, cause of slight water damage to the trail. Very enjoyable ride. Was surprised how few people were on the paved section of trail. Really enjoyed the Trestle Bridge

Spent a wonderful summer morning enjoying the cool lake breeze and astonishing views. I don’t understand why the mileage is posted as 1.9 miles, when I rode approximately 5-6 miles. I started neat the Blue Harbor resort and rode out on the pier to the end. Then I followed the generous lakeside train north past numerous parks and a couple marinas. There is one large hill on the north end, but take it as there’s more to enjoy above that!