Bonanza series's long run. In 2002, "Bonanza" was ranked No. 43 on "TV Guide"s 50 Greatest TV Shows of All Time, and in 2013 "TV Guide" included it in its list of The 60 Greatest Dramas of All Time. The time period for the television series is roughly between 1861 (Season 1) and 1867 (Season 13) during and shortly after the American Civil War. During the summer of 1972, NBC aired reruns of episodes from the 1967–1970 period in prime time on Tuesday evening under the title Ponderosa. The show chronicles the weekly adventures of the Cartwright family, headed by the
U Lazy S Ranch split some of the acreage into farms. In 1949, Lott started flying an airplane to drive the cattle and spray herbicide. In the 1950s, the land was faced with a draught. By 1954, Lott planted 1,400 acres of guar to improve the land. He was also the first Texas rancher to use a roto-pitter to break up the rangeland. Two years later, in 1956, Lott's range improvement program had worked. In 1965, Macy split her section of the ranch and renamed it the Running M Ranch. Meanwhile, the U Lazy S Ranch was managed by Lott's son, Jack Lott. By