Cowboys. Biography Charles A. Siringo entered cowboy rodeo at Riverside Park in Denver under the name Dull Knife. Siringo; Cowboy Detective p.45 Alvin Eugene "Kip True, "oldest cowhand," honored. Post r 4, 1948 p.40 Alvin Eugene "Kips" True, oldest state cowboy dies in Pueblo at 104. Post Ja 14, 1949 p.36 Biog. sketch of bronc-rider Jim Shoulders. Post Empire Ja 8, 1956 p.4-5 Clips: Biog. 0