If you have two individual lists, instead of stacking them, you'll be able reduce scrolling by placing them side-by-side. The example below demonstrates one elegant way to achieve this.
The HTML
<div class="list-columns">
<ul>
<li>Item 1</li>
<li>Item 2</li>
</ul>
<ul>
<li>Item 3</li>
<li>Item 4</li>
</ul>
</div>
The CSS
.list-columns ul { float: right; }
.list-columns ul:first-child { float: left; }