Named after an ancient city in Egypt, Karnack was the childhood home of Claudia Taylor (Lady Bird) Johnson, former first lady of the United States. Today, it serves as a gateway to the mystical Caddo Lake. Covering 26,000 acres, the lake is a swampy maze winding through overgrown cypress, with 42 miles of channel marked to keep boaters from getting lost. One theory is the lake formed behind a Red River logjam. Another is that it resulted from the 1811 earthquake centered on Missouri, a theory similar to a Caddo Indian legend that says the lake was formed at night by angry spirits shaking the earth.