For this question I need you to answer the following: What road owns this loco and what is the type? Who was this loco originally built for and when? What nickname was given to this loco by the Rio Grande? (it has to do with its appearence, what does it look similar to) What is a "first" that this locomotive gave the Rio Grande? (it has to do with its build and how it is arranged (not the wheel arrangement))
Built as Crystal River RR 101. It became D&RG 430. Then became D&RGW 360, Class C-21. The first? Inside frame drivers? The nickname, I do not know. Mudhens were a different class, and that is all which is coming into mind right now.
Well, that went a lot quicker than I had wanted, but Boxcab, you are correct! You were actually close on that nickname, they were called Little Mudhens. The only thing you ommitted was the build date, but Jason picked that up with the year 1900. I have really got to make these more difficult...