I think it looks more like mimulus cardinalis. Isn't mimulus lewisii pink and yellow, not all red as this flower is?
I got it from a seed exchange as M. lewisi, but I think you're right; it's cardinalis.
I've got cardinalis growing in my garden, and that's what I'd say it is, too. I've grown it twice, once with seed from the Theodore Payne Foundation, and once with seed from Thompson and Morgan, so I'm pretty sure mine is really cardinalis.
And like ladyslppr, I was pretty sure that lewisii was pink, perhaps with a yellow throat.