The silver tank to the right and above the rear fender is the cooling fluid for the supercharger. (Super-charger!) They were pulling a matching trailer.
I've read other traveler's accounts of how things only happen when you travel alone; I wonder.
I took an exit off I-40 to check on a boondocking spot. When I got there I noticed another road and followed it. After a while an anthropology professor from Dine College stopped and said it went to Navajo. It turned out it came in the back way past the Vendor Village where Native Americans sell crafts.
I found a nice bracelet and he pointed out where the water is. While getting water the trike pulled in. Although I'm not a trike fan, the folks who drive them are sometimes interesting. So I sidled up, made complimentary noises and got this great picture.
I forgot to ask how many years they've been together, but based on those grins I'd surmise not more than a week. The silver plaque below the headlight read "Las Vegas Trikes." They were on their way back to Missouri.