while several species of Hippodamia are difficult to tell from H. convergens, I believe this one is H. sinuata crotchi, a subspecies of H. sinuata, found generally up and down the Rockies, south to mid AZ, and a little west and east onto the plains on both sides. Overall the shape appears a little less robust than H. convergens, and the strong black marking down the suture line past the basal third points toward H. sinuata crotchi. Yours differs from the typical form, with a lateral vitta on each elytra , similar to H. s. sinuata. But it is certainly within the several variations pictured in Gordon(1).

Nice find!

There are lots of other unique ladybirds around your local - keep looking :)

I believe there's a different ladybird beetle with the convergent markings. Hope you get an expert ID on this one.