Roford 1955 Cynomys ludovicianus March 9, 1955. N. Larimer Co., Colo. Drove N. then W. to Antelope Refuge & looked at a colony in Sec. 23, SW¼, on Achenman's ranch. This was a fine soil with gravel mixture. Some mounds fine gravel. 3 Taridea burrowed holes seen in 10 minutes. About 40 A. of burrows from stream to foot of a hill. All on slope of a few % facing S. or E.N.W. I saw at least 12 out the air cold, half-amount, & 20 mph S.E. wind. Much digging of holes about 2" deep near burrows - apparently to get at roots. P. Baldwin shot 7/25 with shotgun. Open area day appearing but some fresh eating of leaf edges. Pasture depleted - 8"-12" between little grass. Shrub (Mod. Atriplex) but browsed to about 6" high. Burrows seemed very widely spaced. Some Pogonopymus mounds in same area. Took 2 photos (black & white) of area. Should return here to get spacing, vegetation, & population closer on depleted range. Rudy Achenman told me of this colony, another in Sec. 10 about 1½ mi. W. of Achenman's house. I later visited that one. It was on S. side of road and at least 40 A. in extent. Sec. 10 This was esp. very slight slope. Rudy said it had started about 1½ yrs. ago (he didn't know any C.L. out yet !). A man at Clarence Murns's said it had started about a year ago. I saw 10+ per acre out the overcast & prob. < 40° F. at 3 p.m. Shag revisit this as recent colony. II Drove N. from Achenman's thru rolling grasslands to bluffs where old eagle nests (near Wyoming line) but saw no more C.L. Sheep sign abundant. Why are C.L. so restricted? - must not spread fast or would be more widespread in spite poisoning. Social factors may slow spread of species. II Visited Clarence Murns place. Tropen bloom absent. One man there said now no C.L. on Murns place about