Just rode the entire trail with my daughter, Oct 16 and 17. We started in Council Grove and rode East. We were on hardtail mountain bikes.
From Council Grove to Osage City the trail is in absolutely perfect condition. It's wide, (10 -12 feet),smooth, hard and fast. Many times I thought I was riding on pavement. I even locked out my front fork because I didn't need it. All the bridges are new. Guys with road bikes, have fun you'll fly. Congratulation to the Parks Dept for all their work, this portion is as good as it could be.
Then you hit Osage city. Oh boy, time to unlock the fork. From there to Vasser it's pretty rough. You come to HW 31 on the East side of Osage City and your looking at a overgrown weed patch along the junkyard. The sign said it's the trail so we went. There is still a pretty good gravel base so just pick your line and go. Then heading east go through the parking lot at the grain elevator and the trail stops at 5th st. There is no signage. We just kept going straight because there were no " private property" signs. It's all grass no path. Then at 6th street you have to detour to the south on Lakin Street. Ride Lakin east and turn left at Sonic then North back to the trail. It's a very short detour, no big deal.
From here to Vasser, again it's hit and miss. Some sections are OK and others are pretty rough. We were lucky because it hadn't rained in a while and trail was bone dry. There are lots of sections that are just dirt that would very tough if it was muddy. There was one section just as you go over the bridge at HW 75 that was very fine deep loss dirt. It was dry and we still had to ride in the weeds on the shoulder where the ground was hard to get through. If that was muddy, forget about it.
From Vasser east the trail goes back to the " improved" condition.
We got off at HW 368 and went north and camped at Pomona State Park.
Very nice park with facilities. There is also a good restaurant on the left by the motel and golf course. Open all day.
Back on the trail in the morning and through the only tunnel on the trail under HW 268. Like I said from here on the trail is back to the " improved" condition. Not quite as nice as from Council Grove to Osage city but still very good. Just a few more bumps and chatter.
Lot of dead trees down but that was because of the bad wind storm we had the night before. We weren't in a big hurry so we just cleared them ourselves.
I did run into a parks truck doing maintenance and got a lot of good info.
That bad portion through Osage City is waiting on some bonds for funding and that eventually the trail is going to have bathroom facilities, water and mile markers just like the Katy. They already have mile markers from Ottawa to Osawatomie.
Anyway heading east we ran into a big detour at Iowa rd. The trail is closed there or should I say non existent. You have to take the detour which is well marked and takes you out on the country gravel roads. The roads aren't bad. It's not the " big" gravel you think of when you hear " gravel road" but fine crushed gravel very similar to what's on the trail. The detour is about 3.5 miles and you get back on the trail at Louisiana Ter. At this point your about a mile West of Ottawa.
From Ottawa to Osawatomie the trail is in great shape but some of the bridges haven't been replace or updated yet. There are about four or five with no railings. Most aren't very high but one is about 30'. I just mention this in case someone is taking some young kids. On that big one I don't know why they couldn't a least put in a couple posts and at least string some cables just so there is some protection.
The trail now does go all the way to the Karl E Cole baseball complexe and ends there in nice big parking lot.
I hope this update was useful. Reading older posts when I was researching this trip I was expecting the worse but i can tell you that we had a great time and the trail is in great shape with that one section and detour as the exceptions.

Carl Spahn with daughter Madison
Kansas City, Mo.

Rode the trail starting in Osawatamie. Trail was in great shape, though some parts had a lot of leaf coverage. Despite this, no issues with surfaces or slippage. Such a peaceful trail to ride. And it flows super fast.

Rode from 119th and Northview to SM park. Path is fairly well maintained but has the usual bumps in the asphalt that are common along creek trails here. There are some hills as the path gets out of the creek bottom in some areas. There is a nice canopy along most of it with several turn outs to local parks. Once inside SM park, you can cruise the roads and paved trails there.

Very nice trail, populated with walkers and bikers on a pleasant Sunday afternoon. Almost completely shady and very smooth concrete. The description shows the trail going from 11th street to 23rd, but it actually extends an additional mile south to 28th Street. Eventually it will connect with other trails on both its north and south terminals to become part of the Lawrence Loop. As of today, there is well placed signage indicating a two block zig zag at the south end where it reconnects with the South Lawrence Trafficway trail.

40 miles of outstanding trail. Rapid improvement of Flint Hills nature trail due to its designation as a state park. From Osage city to Allen the trail is 20 feet wide of crushed lime stone. From Allen to Council Grove 15 feet wide crushed lime stone with rock formations and fossils on both sides. Bathrooms,food, and water in Osage city, Allen, and Council Grove. Camping available in multiple sites along the way.

This trail is perfect for older, beginner bicycle riders, which my wife and I are. The park is also lovely.

Having already biked from Ottawa to Welda, I went from Welda to Humboldt round-trip so as to complete the last remaining segment of the trail. Technically, the section from Iola to Humboldt is the Southwind Trail Trail, however it functionally is an extension of the Prairie Spirit. Regardless, I remain impressed with the condition quality of today's 26 mile section. The trail was packed down with minimal loose gravel, so as to allow for a surprisingly smooth ride. Simply excellent condition. Considerably more tree cover than I expected as well, which was quite welcome on a hot day. Several sections had foliage covering the trail to create a tunnel effect, which was a treat. If you have the opportunity, do yourself a favor and treat yourself to a trip on this very well-maintained rail trail.

On the trail at 127th by 8:00 am riding to nall ave...on the way back 8:50 am the trail was very busy with walkers, runners and cyclists. Many cyclist flying by little kids with no trail manners. Normally we find this trail very nice to ride! Enjoyable easy ride.

Trail is nicely maintained with little-to-no foot traffic. Nice option for a 17-miler.