Jim, You might look for a copy of *Colorado Rail Annual No. 14*, which contains "Lake City Branch," by Duane Vandenbusche and Walter R. Borneman. PP 25-110 of the volume. (Which also contains an article on the three business cars now available for charter on the D&SNG, and an article on the Creede branch.) On page 51 is a map of the D&RG yard at Lake City, traced from a D&RG Valuation Map by E. W. Robart. The yard is quite simple, with a loop to the northwest of Henson Creek and the Lake Fork of the Gunnison River containing a spur with a track scale, and a two-stall enginehouse. Another spur ran west and south of the depot. I've never seen any evidence of a wye at Lake City.
Happy Researching! Charlie Mutschler