Cold, Cold Crevasse

Cold, Cold Crevasse is an area off-handedly mentioned in Cool, Cool Mountain, by a sign near the beginning of the level. The most common interpretation of this name is that it belongs to the slope that precedes the sign, although it does not match the description of a crevasse.

The recent boom in Super Mario 64 conspiracy theories has brought Cold, Cold Crevasse back as a discussion point, with many theorizing it to be an unused or scrapped sub-area for Cool, Cool Mountain.

Existence
There's a sign nearby the broken bridge at the beginning of Cool, Cool Mountain. On it, it reads, "Warning! Cold, Cold Crevasse Below!" and below this area is a large slope that leads downwards. It's not much of a crevasse leading some to speculate that this isn't the Cold, Cold Crevasse the sign is referring to. Considering that the name "Cold, Cold Crevasse" follows the common naming conventions for Super Mario 64 stages, it could instead be referring to a removed area erroneously still mentioned due to a developer forgetting to change the text on the sign. A crevasse is a deep open crack; this doesn't fit the description well since there is no other side that would make it qualify as a giant crack.

jefftastic's Video
As apart of jefftastic's videos documenting Super Mario 64 phenomena, one of his videos features Cold, Cold Crevasse. He seems to accidentally stumble across a warp to the area while trying to bring the penguin across the slope in Cool, Cool Mountain.

Cold, Cold Crevasse is presented as a secret area within Cool, Cool Mountain featuring only one star. The level has the player trek through the internals of a cavern, where Spindrifts are found to help the player ascend through the tower. The kind Chief Snowman signs the two signs that appear in this level. The star collected in this level is considered one of the secret stars, much like The Princess's Secret Slide. The level does not appear to be fully finished, since Mario is slowed down by snow even on non-snow parts of the stage in addition to the area being very short and partly empty.

Reportings

 * Everything in this section should be taken with a grain of salt. These are all unverified claims.

Report No. 1
I found this place when I was playing on my copy of Mario 64. I found it when I tried to do the Speedrun Strat when doing the Li'l Penguin Lost star (The one where you slide off the "Cold Cold Crevasse" and then jump back onto the platform.). However, I ended up falling. Then, it took me to this place. The happy music of Cool Cool Mountain was gone, replaced with the wind blowing. Mario landed onto the snow. I looked around to see the place was just one giant snowy platform engulfed in white fog. No enemies, no coins, no stars - nothing. I heard the "Di-ding, di-ding" (The one when you are on low health underwater) in the distance. I started running in the direction of that sound. Mario's health started falling and he started slowing down. With Mario getting weaker and weaker, my screen started getting covered in snow. When Mario finally reached the sound, he was crawling on the ground, with only one hit-point left. The source of the sound turned out to be a baby penguin. It was completely gray and it had no eyes - just black holes. Then, another baby penguin appeared. And another one, and another one, and another one. Soon, there were a total of 10 penguins surrounding Mario. A speech box came up, which said "All the players dropped us into this ravine. Join us, Mario. Be free, along with us. In heaven." The camera then zoomed onto Mario's face, who was barely alive. A smile appeared on his face, before he passed out, and subsequently died. All the baby penguins vanished into dust. Then the N64 turned itself off.