You could go over the sunrose lightly with a hedge shear, above the foliage to take away the spent flowering stems. No advantage to cutting back the wild roses, these are not heavily pruned bedding types. More constructive to mulch around them instead.

Extensive patches of wild roses occur in your county, if successful your planting will also sucker to produce a large grouping over time. You may find it poking up through the path in future, if left in that location.

For future reference, the sunrose is typically sheared back immediately after flowering. That removes the unsightly spent flower stems and tidies up the plants. Often encourages a later summer rebloom as well.

Thanks guys!
And I'm hoping the nootka rose will spread. At least behind and to the left of what you see in the photograph.

There are solid patches in the vicinity as big as the whole area visible in your picture. It would not surprise me if some of these rose thickets were made up of a single genetic individual, in the manner of aspen trees or honey fungi that spread over acres in time.

For a location to see some of these big wild rose colonies...

Here is a link that might be useful: Hovander Homestead Park, Whatcom County Washington