The 5 species of coneheads in Iowa are bright green like other katydids, but have a forward slanting face and their wings are more narrow. A good view of the underside of the "cone" or protrusion between the antenna, is very helpful for identification to species. The Sword-Bearing Conehead has a long cone with dark margins. The most similar species is the Nebraska Conehead, which has larger dark areas on the cone. Ovipositor length can be also be helpful for identification of females. The ovipositor in Sword-Bearing Coneheads is 27.5-33 mm, longer than hind femora which are 22-23 mm (Blatchley 1920). The ovipositor is usually not much longer than wings or shorter than wings. Coneheads are often green but the brown morph is not uncommon.
Currently, or in the past, iNaturalist seems to have tended to default to Neoconocephalus ensiger for any Coneheads in Iowa, so there are currently many coneheads identified as this species which I am not sure are accurate.
Coneheads can bite so take some care with handling.
Cone patterns in Neoconocephalus: https://orthsoc.org/sina/g185a.htm
Blatchley, W. S. 1920. Orthoptera of Northeastern America: With Especial Reference to the Faunas of Indiana and Florida. Nature Publishing Company, Indianapolis, IN. https://www.biodiversitylibrary.org/bibliography/1700
Statewide. This species is distributed in a band across the northern eastern U.S. and southern Canada. BugGuide and iNaturalist observations have expanded the known range.
Mesic grassy areas, fields, roadsides, usually in tall grass or herbs, not in undergrowth or trees.
Froeschner (1954) stated that it occurred in dry sandy prairies, but Blatchley (1920) listed habitat as tall grass in ditches or near damp prairies and SINA listed habitat as wet grassy fields and roadsides. I think this species may be a bit of generalist, occurred in a variety of grassy environments from wet to dry.