Greene's cabin was the trip's next attraction.
Down the hill from the Colosseum Mine, Greene's cabin was occupied from 1900 to 1920. "Backcountry Adventures: Southern California" tells us that Mr. and Mrs. Greene used one end of the cabin for their quarters, while the middle section was a kitchen that helped serve the miners working on Greene's gold mines to the north of the cabin. The diggings might be accessible, but we didn't stop to find out.
Cardboard on the ceiling created some dead air space that helped insulate the interior from the weather's moods. Summers are toasty here, but much milder than down on the valley floor. Winter weather can be downright chilly, as it was during our visit.
This spot isn't that far from I-15, but it seems a world away. You could do an out-and-back trip from Primm to the Colosseum Mine and Greene's cabin in three hours or so without needing to scurry along. Chances are you'll want to tarry longer. There are plenty of vistas to take in and other bits of two-track that beckon.