“Static” Child Menu with Accordian

I’ve figured this out. I think one of the examples in the WordPress Codex is supposed to be the solution but simply doesn’t work.

Here is what worked for me:

               <?php
                    if ($post->post_parent) {
                    $ancestors=get_post_ancestors($post->ID);
                    $root=count($ancestors)-1;
                    $parent = $ancestors[$root];
                    } else {
                        $parent = $post->ID;
                    }
                        $children = wp_list_pages("title_li=&child_of=". $parent ."&echo=0");
                        if ($children) { ?>
                        <h3><?php echo get_the_title($parent); ?></h3>
                        <ul id="subnav">
                            <?php echo $children; ?>
                        </ul>
               <?php } ?>

Which then outputs this:

About Us

Our Mission
Strategic Plan
Our History
    History of Oak Hall

‘About Us’ is a header using the title of the topmost parent page. The menu underneath is static, no matter which page you then choose within that submenu.

Some CSS styling was then used to indicate the current page and separate the children of those sub-pages.