Elizabeth, you may want to consider backpacking to Juniper Flat, or Boulder Meadow. Both are on the Pinnnacles Trail, but you'll come to them before encountering the strenuous elevation gain of the Pinnacles Trail. At either of these areas, you are way from the Chisos Basin Lodge and campgrounds, and will have some fabulous views of Casa Grande and the other peaks that ring the Chisos Basin. Check out this link for more info: http://www.nps.gov/bibe/planyourvisit/chisoscamps.htm
Also, the Laurence Parent book, "Hiking Big Bend National Park," provides much information on the various trails, along with charts of elevation gain and loss on each trail. Whole Earth, REI, and other similar stores often carry this book.