Iowa Code § 572.7: In case of internal improvement.

When the lien is for material furnished or labor performed in the construction, repair, or equipment of any railroad, canal, viaduct, or other similar improvement, said lien shall attach to the erections, excavations, embankments, bridges, roadbeds, rolling stock, and other equipment and to all land upon which such improvements or property may be situated, except the easement or right-of-way.