Mike, as far as I can piece it together, the Alamosa Turntable at the end of the narrow gauge era was a 100 foot one, which would accomodate an L-131.
The CRRM reprint of the 1923 Offical Roster 11 states that the Alamosa TT was 65'. In the May 17, 1924 issue of *Railway Age* is an article (pp. 1193-1200, 'Denver & Rio Grande Western Rebuilds Shops') which lists improvements across the system which were begun in 1923, and which were nearing completion by May, 1924. Discussing Alamosa, the article states: "It was also found necessazry to replace an old 65-ft. turntable with an 80-ft. balanced-type table." Which suggests the 80 foot table was in place in 1924.
By 1928 the 80-ft TT had been replaced by the 100-ft table, as indicated in the 1947 map of the Alamosa yard structures that is reproduced in John W. Maxwell & Charles S. Small, *Rio Grande Narrow Gauge in the Summer of 1941,* (pp. 106-108). The index notes the retirement of an 80-ft TT in 1928, and its replacement with the 100-ft table existing in 1947.
Hope this helps.
Charlie Mutschler
-30-