Paul,
My best deduction on these birds is that they’re Tundra Swans, and I’m disappointed to conclude that. While a couple characteristics point to Trumpeter (one of the swans has the wedge-shaped Canvasback head and the black eye seems to be contained within the mask), the preponderance of characters pulls me into the Tundra camp:
While Trumpeters never have yellow lores spots and Tundras usually do, I found estimates of 10-20% of Tundras lack the yellow spots. I’ve always heard the lack of the spots is not diagnostic for Trumpeters.
The orange-pink grin line, called the tomial edge (my new word for the day) is present on Trumpeters and some references say on all Tundras, too.
Some Tundras can have a less concave bill and more wedge-shaped head.
The apparent lack of a size difference in the bird with the most strongly wedge-shaped head bothered me. That close to a Tundra, the size difference between the two species should be apparent.
The suspicious bird also had somewhat pointed head feathering, the feature I’ve found to be the best one to ID a Trumpeter. Trouble was, I found references that cast some doubt on how good that feature was (and other potential ID points like body and neck posture, head/bill shapes, lores color, blah, blah, blah).
I was really sold for awhile on the one bird being a Trumpeter, and the others obviously not. But then I dealt with the slim chances of a Trumpeter being with three Tundra Swans that all have black lores and the Trumpeter ID seemed unlikely again.
Ultimately, I made my shaky conclusion based on nothing diagnostic, but weighed each characteristic, the possibility of each occurring in each species, and the fact that nothing pushed me strongly into the Trumpeter camp. I sure would prefer to feel a stronger “umph” when I come to a conclusion like this.
I totally discounted the juvenile. Juveniles are even harder to distinguish, and one reference I used said juvenile Tundras may have pointed forehead feathering until they’re two years old. The bird you photographed is obviously in its first year.
I’ll admit to tearing my hair out over these birds. I might just pay a visit to Wolf Creek tomorrow, but I bet there’s no Sago Pondweed or other aquatic vegetation in those ponds and not much for the birds to eat. It might not be a good place for them to stick around.
Kris

Paul - Great find! Yes, I would ID these as Trumpeters. I think the bill is long enough and straight on top. Also, trumpeters tend to hold their neck in a straight position instead of slightly curved. Also, the base of the bill is black in the juvenile - not good enough by itself, but if it was pinkish the Trumpeter would be eliminated. I was also concerned about the rounded pattern on top of the bill between the eyes - I decided all of the other characteristics probably out distanced this one "glitch." Also, the other forehead photo was more pointed. I didn't copy Kris with my "take" as I didn't want to bias her - I'm also interested in what she says. Kris and I along with others spent the day at Compton's Knoll looking at and talking about Bald Eagles. We had a great day with a large number of observers. Keith