Rofoed 1955 Cynomys ludovicianus February 9 St. Collins, Farrier Co., Colo. Interviews Dave Crowe of Brush, Morgan Co., who has been F&W rodent control man in N. Weld Co. since 1948. He marked a map for me showing location many poison towns & a few not treated. He was quiet, intelligent, & well informed. He also had worked in Park Co. (about 1945), Morgan Co., Logan Co., & others. One in Morgan Co. he poisoned a town that had at least 4 all white prairie dogs. As to dogs gather- ing in one area poisoned town, he thought they would not until following repro. season. Poisoning usually not done until mid-June or later to give chance all young to come out. First emerge about mid-May, usually 4-5 or 6 suckers in time births (sayater too) in Weld Co. He said over. litter size 5 usually presumed that this probably marginal. He had recognized no tendency to reestablish formerly ploughed ground. They seemed to start in heavily sodded law areas & spread supralooper. Their own grass apparently doubled and not cut by Q.L. the they cut down sagebrush. Much difference in density burrows. On 3000 A. of Warren Live Stock Co., averaged about 20 A./lb. of 1080 roots (rough 3-4 A.? ), because low density. The big town on Henry Prange place (Sec. 33) poisoned 3 years ago, then last year had many dogs & again poisoned; probably some left still there. Jim Lawrence town near house poisoned 1953 & no complaint last year (prob. good kill). %o kill constantly less, Crowe said. One town lasted late June but later visited & found little effect (young out later?). Late breeding 1954 apparently.