Have any of you ever built a decorative footbridge? Any advice?

Have any of you found a source for thermally stabilized lumber? ( better than penetreated)
I heard there was a source for EcoVantage lumber in San Antonio.

I have an elevated path 48" wide behind my house crossing a drainage swale.
I plan to remove the culvert ,create a 60" gap faced with stone and bridge it with an arched wooden bridge.

Need to improve drainage, culvert reaches capacity.
I have the tools and experience to build it, just looking for advice.

Thanks!

Great idea & project
Only Google gives me a hint buy.advantagelumber.com
but
Forever Redwood/Cypress would be easier to find sellers & in/near Austin ... even prefab redwood foot bridges can be found @ $2000+
Dallas Cowboy was the redwood source in Austin in-the-day now also in Dallas, etc. https://www.lrjlumber.com/products/

Please post any successes so I may pass it on if a client desires such.

Try Lumber Plus in Houston. They have a nice thermally treated wood called ayous that is reasonably priced (less than $4.00/LF).