Here’s the response from a PhD who specializes in Orthoptera. I know this answer will not satisfy Jason.
Melanoplus and the subfamily Melanoplinae in general are difficult for non-experts to identify. The primary morphological characters are the male genitalia. The shapes of the male cerci are the most recognizable characters from photographs, as long as the photos show the small cerci or at least one cercus. The best resource for identification is the out of date and out of print book by J. Helfer; “How to know the grasshoppers, cockroaches and their allies.” Wm. C. Brown Company Publishers 1953. The picture keys and illustrations in the book are useful to identify North American Melanoplus and other melanoplines to the common species and species groups. Otherwise, people can look at images on the BugGuide web site, starting with a search of the genus name Melanoplus. The genus Melanoplus is currently being revised by a small team of entomologists, including a phylogeny and new species descriptions. Their results will not be out for several years yet. The best thing that iNaturalist can do is to recruit taxonomic experts for Melanoplus to identify submitted photographs. Sorry, but this is one of those many groups of insects that really do require expertise to identify. They are far from birds and butterflies on ease of identification to the species level.