Background (such as I recall it): ummm... Remember very, very little, other than having done it. With Janice, and her sister Mimi. Late summer day hike on Rainier to the ice caves.
In the right-hand photo on the top row here you can make out a sign warning people not to go in the ice caves because of the risk of collapse -- one of which you can see towards the end of the set.
Anyway, we went in as far as we could.
Cold, and dripping water constantly. The light inside through the ice overhead was simply astonishing.
Dated Ektachrome slides.
These might have been what's known officially as the Paradise (Glacier) Ice Caves -- a Google search for "Mount Rainier Ice Caves" doesn't seem to turn up any others.
A quote from that web page as saved by the Internet Archive Wayback Machine: "As of May 28, 1978 the length of the Paradise and Stevens Glacier Caves System was 8.23 Miles (13 1/4 km) or 43,560 Feet long. This was the most ever on the map at one time. When the Paradise River section of the cave was segmented at Surprise Entrance during the following summer, the length figure dropped to about 7.4 miles (I 1.9 km) but regained the gate figure in the winter of 1979. The depth (as determined by topographic maps) dropped from 855 feet to 490 feet, and similarly returned to the earlier figure. More than 15 miles of mapping was required to reach these figures and much remains to be accomplished. Because of change in cave system in the recession of the glacier. "From 1980 to 1991 Charlie and other IGS Members made two or more trips a year mapping the changes of the recession of Paradise and Stevens Glaciers. The Glaciers are in rapid retreat up the mountain. IGS Members also map the change in the caves entrances during this retreat of the Paradise and Stevens Glaciers..."
And then again, maybe not. These ice caves seem to be much lower down the Mountain than those described above, and not nearly so large in scale. But they were in ice, and they were really awesome anyway...