I note with interest that the Palouse to Cascades State Trail (Washington, USA) is getting gradually more complete. Two long trestles opened in the last year. Few road detours are now required.

Is this a practical bike touring route? The distances and climbing are reasonable. The surfaces I see in photos seem doable on my recumbent bike. I have no trouble at all with gravel roads, especially gentle rail grades. Are there long sections of unimproved ballast? Is the trail usable after a big rain?

I would like to hear from experienced bike tourists who have done this trail and who can compare it to touring on back roads in the same region. It seems like it would be a fun route, allowing me to bike from downtown Seattle to Spokane almost entirely on the old Milwaukee Road railway grade, with tunnels and trestles. Where else can I pedal through a 2.3 mile (3.7 km) tunnel?

Official park web site: https://palousetocascadestrailmaps.com

Your link is actually an unofficial site maintained by a fan of the trail; it's more up-to-date than the official site. I've only ridden a short section of the trail (along Rock Lake) and it was great. It was also closed, I found out later, so do your homework. The undeveloped part that I rode was rough but rideable on 35 mm tires.

The Beverly Bridge across the Columbia opens this weekend, which will make riding the trail end-to-end a lot more practical, as the only alternative was a scary shoulderless bridge on I-90.

There are some detours east of the Columbia due to private property and burned trestles, but the number of cars you'll see on the roads out there is only slightly greater than the zero cars you'll see on the trail.

If you Facebook, there's a Friends of the Palouse to Cascades Trail group that's pretty active, and they can answer any question you might have.

Thanks for the tips. You mentioned that the trail was unimproved near Long Lake. That appears to answer my questions about the color coding of the RWGPS route.

The purple dashed line must be unimproved ballast. The red dashed line must be improved gravel trail. It appears that more than 1/3 of the trail east of the Columbia river is unimproved ballast. Hopefully much more will be improved a couple years from now...