Beginner Gardening: Need help with achieving a privacy border, 0 by Bamazone7

Bamazone7 wrote:
New to site, lots to ask, hoping for help!

My problem: A bare backyard property line where our view is of neighbor's fenced swimming pool.

My plan: Thought I would start by removing some of our lawn close to property line to make a curving garden bed outlined in bricks or stones and just add trees for now (fill in as can with shrubs, plants, etc., later). Since my neighbors also have to live with the view I create, I certainly don't want to carve out too big/small of a bed and place the wrong tree in type, size, location, number, etc. Found a photo that love using river birch trees.

The area: Topic pic shows the west end of our back yard and the open area where I'd like the border. It measures approximately 70' in depth starting from the back corner of our home (japanese maple on the corner) and ends down in the far wooded corner (see where a fence ends). It gets full sun and we live in zone 7a. Our house is pretty much lined up with the neighbor's with about 50' between the houses.

Question (finally, right!): I really like the look of river birch trees and would love to use some but am concerned that they will grow too tall for this area. Read that there are dwarf birch trees; thought could plant these closer to our houses and then the larger birch trees further out toward the wooded area. Good or bad type tree to plant between yards? If right type tree, any suggestions on how far from houses I should begin planting, how many I should plant and in what pattern to achieve a nice affect? Opinions and suggestions are appreciated!