Saw this bug this morning in Colorado. Looks like a giant wasp.
That is a horntail, family Siricidae. https://www.insectimages.org/browse/taxthumb.cfm?fam=455 They are a family of sawflies. Not technically wasps, but they are Hymenoptera.
Yeah, she looks dangerous doesn't she. However, the 'stinger' is used for ovispositing eggs in wood. These wasps do not sting.
This species is called Pigeon Tremex Horntail, Tremex Columba.
Nice pictures and very interesting information on the website below, however the images have copyrights, so I can't include them here.