I wanted birch for the same reason. I ended up getting river birch, which does *not* have the white bark, but still has interesting peeling and color. It has performed beautifully. I know everyone says aphids, aphids, aphids, but I'm in Bellevue and there are birches all over the place. I've heard that the himalayan super-white one with bluish leaves is the hardiest here. Unfortunately, they're the most expensive.

The hillside wouldn't be the right place for river birches. As you know, even though it rains a lot here, we don't actually have a lot of inches of rain...and a river birch needs it wet. But you didn't want a river birch anyway, did you? If you want to look at some thriving birches, and get an idea which ones will do well where, drive north on 130th Ave in Bellevue up into Bridal Trails neighborhood, and across the Lake Hills Connector off the SE 8th exit in Bellevue. You can take pictures of the ones that best match your conditions and get a variety name from the nursery or from "Name that Plant!"

How about some flowering trees, like cherry or redbud? Redbud and dogwood are both native here, and the dogwood is pretty fast. Big leaf maples grow like they're hybrids, but then, you said *small*, didn't you? I can't think of anything that's both small and truely fast-growing, so I'll let more knowledgeable folks make some more useful suggestions.

Just an aside - the folks at the tree nursery in Woodinville were very helpful. And Angelo's in Bellevue usually has some good sized himalayan birches for a decent price.

Unless you need something smaller-growing, 'Jermyns' would be a good one to try.

"A very vigorous, medium-sized, broadly conical tree; the very fine, white bark is retained into maturity. Catkins long and showy, up to 17cm. Selected in our nurseries from plants received from Belgium. A specimen has reached more than 20m in the Sir Harold Hillier Gardens and Arboretum (2000)."

--The Hillier Manual of Trees & Shrubs

Here is a link that might be useful: forestfarm - Betula utilis var. jacquemontii 'Jermyns'

Hey thanks for the recommendations. I love river birch, but you are right that it is probably too dry a spot. I reread my post and I see that I was not clear about the size the birch can be. The smaller trees I plan to put in will be in front of the birches.
I have seen the mess birches can make with all the honeydew the aphids and ants farming them can make. But this area is not near the house, driveway, or garden area. I actually look forward to the birds it will attract.
I looked for pictures of 'Jermyns'. It has nice bark, and I like the term very vigorous. I would like to plant them in clumps or at least in a group. Am I correct to call it a Himalayan birch?

Clone of Himalayan birch. Heavy aphid drip seen mostly on European birch.

The variety is what is usually available, rather than the typical plant.

Yes, Himalayan birch is the right name.

For a pretty good list (you wouldn't be using the UK suppliers listed, of course, and not all of the Himalayan birch cultivars are likely to be available stateside)...

Note that if you "Click on a plant name entry to see its details in the RHS Horticultural Database" and then click on 'The Award of Garden Merit' on that second page, a third page opens with a basic description of the plant, for example

"Medium-sized deciduous tree, slender and open in habit, bark peeling, pinkish to coppery red-brown, with white bloom. Leaves oval, strongly toothed, turning yellow in autumn. Flowers in brown catkins"

for B. albosinensis.

Here is a link that might be useful: RHS Plant Finder Search Results

Will Betula papyrifera--paper bark/canoe birch do well here?
what conditions does it need?

Western paper birch native to Northwest Washington, many are seen along sections of I-5 north of Everett. National Champion used to grow just east of the same freeway in Bellingham. In 1996 it had a trunk about 5 ft. thick.

As with other birches a moist soil produces best growth and summer appearance.

In 1989 it had a trunk about 5 ft. thick.