I thought Harison Yellow; surely it's ubiquitous in WY, but it only blooms in the spring, does not repeat. Father Hugo, think it's always single, doesn't repeat either I don't think.

If you can manage to get a photo of one, the long time part is intriguing, maybe you could post it and someone would know.

Yellow roses are a particular favorite of mine, but apart from Peace (not totally yellow and not necessarily hardy in WY), I can't think of what it could be. I have the Austin Charlotte that is one of my best performers, blooms almost continuously, HMF says 1994, may be the only one on this forum that grows it. Golden Celebration, Teasing Georgia are the only other names I can think of and think they might not be hardy in WY and relatively new.

Come to think of it, I have not seen many yellow roses in gardens here except the public ones, Harison and Father Hugo being the main exceptions and precious few of those left. Most grow red or pink if they grow any at all.

Father Hugo (Rosa hugonis) does not repeat.

The thing that makes this both interesting and frustrating is that it's yellow and repeats and is early blooming. From what I've grown and read about, the repeats part is the hardest to match up.
There is a nursery not all that far from you (by western US standards) who started in Denver metro area and who are now in Utah. You might want to go through their website and contact them and find out if they've found a similar rose.

Here is a link that might be useful: High Country Roses

Might be a Brownell. When I was a kid, all there was was Gurney's catalogue-no nurseries. I can remember an old lady that grew a yellow rose. It was hybrid tea shaped and survived every winter.

You aroused my curiosity. Brownell bred a lot of different roses. Could it be Yellow Curls? HMF is asking for a photo of it but gives a good description.

As usual they give z6b-9b. It is a hybrid tea, can't find much else about it on the web except the two links, no photos.

Some of these are oldies but goodies and might be hardy for my zone. On one zone map, WY is predominately z4 with parts z5a and smaller parts z3. Here's another link:

http://www.geocities.com/rainforest/vines/7707/brownell.html

Here is a link that might be useful: Brownell Yellow Curls Rose

Here's a picture of a yellow rose taken at a ranch in Cody, Wyoming. Does this look like what your mom's seen?

Here is a link that might be useful: wyoming yellow ranch rose

here's a full bush shot of the same rose

Here is a link that might be useful: yellow bush shot

Thanks. I emailed the link to the picture to my mom. She just returned to Texas for a wedding. She's going back to Wyoming in July and would take pictures for me. She and her husband is building a house nearby Newcastle (I think). That's southeast area of Wyoming.

Wow, what's not to like about that other than it may get too large for some spots? Looks pretty carefree and hardy.

I hope somebody will know what it is. In growth habit, it's nicer that Harison, well it's just different and repeat would be a bonus.

I'm pretty sure that's Persian Yellow, which doesn't repeat.