Where is this growing?

In my garden near Portland, Oregon. Native habitat unknown.

Could it be robusta?

I did the same thing: it must look different at different stages. I’m still not 100% confident, but it puts it in a ballpark, at least.

Robusta looks promising.

Or maybe G. tibetica? No, the rows of black dots in the throat look just like robusta.

It looks right to me. The petals were throwing me off. It has 6 petals instead of 5. The middle flower has 7 petals. Here's a few pics of the local species here

Fringed Gentian, Gentianopsis crinata. It's biennial and I grew it in a bog pot. A lot of people told me they have a difficult time growing them, but I just ignored them after sowing and they surprised me. I didn't recognize them last year, but I was happy when I realized what they were. They like calciferous fens.

Bottle Gentian, Gentiana andrewsii. The flowers never open and it's fun to watch bumblebees forciing their way inside to reach the pollin.

Prairie Gentian, Gentiana puberulenta. I haven't had success with this one yet, and seeds aren't available currently.

Soapbox Gentian, Gentiana saponaria. The flowers of this species only open slightly. I like the stripes.

Pine Barren Gentian, Gentiana autumnalis. This is native to the southeastern states. This gentian has a lot of variability in the flower colors. They can be much darker with deep green throats, and they have the spots going on, like robusta. Do you have any Frasera species in your area? We have one eastern species, Frasera carolinianus. It takes from 12 to 15 years to flower, and then they die. I don't think I have the patience nor the time to start any now. Gentians are a lot more difficult than milkweeds, but some native milkweeds are difficult too.

The one main difference I see between this plant and the photos of robusta are the upper leaves look shorter and slightly wider on the OP's plant. It could be normal variation, or this plant might be a hybrid with something like Gentiana tibeticum?

Garden hybrids are a big problem with species lilies also. Most of the photos being shown on the web are obviously not the original species. Not a good time to be a purist, I guess.

Jay, here is a link to an article I wrote about Gentianopsis crinita, back in the 1990s. https://www.nargs.org/faq/gentianopsis

Thanks for the crinata link lilydude! I was questioning if the gentian was a hybrid, because they hybridize easily with each other. The blue Gentiana andrewsii here often hybridizes with the Cream Gentian, Gentiana flavida, and some of those hybrids are quite beautiful.

Cream/Pale Gentian, Gentiana flavida

Gentiana andrewsii x Gentiana flavida.