It’s a sad “Happy Trails” to Dale Evans, the spunky “Queen of the West” wife to “King of the Cowboys” Roy Rogers, who died of congestive heart failure in her Los Angeles desert home on Wednesday. She was 88. The legendary screen queen, who made her first movie with Rogers, “Cowboy and the Senorita,” in 1944, appeared in 35 movies with her husband of almost 51 years (Rogers died in July 1998 at age 86). Evans and Rogers were the definitive cowboy couple, hosting TV’s “The Roy Rogers Show,” which ran from 1951 to 1957 and, later, “The Roy Rogers and Dale Evans Show” and “Happy Trails Theatre.” The native of Uvalde, Texas, who was born Frances Octavia Smith, got her show business start doing radio singing jobs and later began work in Hollywood. Evans and Rogers co-wrote their “Happy Trails” theme song and recorded more than 400 songs during her prolific career. She also authored over 20 books, including the best-selling “Angel Unaware,” a memoir about her only natural child with Rogers, Robin, who died of complications from mumps before her second birthday in 1952.