I took the SWC in December to Riverside [arr. 7a.m.!!] from KCY. The scenery was awesome once the sun came up in Colorado, then across NM. Must admit that after awhile, I got tired of seeing the same scrub landscape...but it was certainly *different* than what I am accustomed to here in the midwest. Still good and interesting. Saw a few pack of coyotes running just off the tracks. Went through the Raton Tunnel during the day, and most of the nice scenery was visible. In Sept. you'll be seeing even MORE than I did. On the way back, the sun didn't rise until Arizona, and even then...I missed Flagstaff totally, but again - the Raton pass and Glorieta pass are daytime events. You'll have a great time. Have fun!