In the previous episode of America Unearthed (S03E04 Montezuma's Gold) they were diving in Utah. It was some little pond where a protected species of snail lives. I'd seen an episode of some other series where this same place was investigated. This is one of those places that have an alleged curse associated with it, I'm sure there's been talk about that place in the forum but I don't remember the exact name of that place so can't do a search.
*spoiler* The underwater cave was blocked because of too much silt. They dredged it but it was not effective in removing this type of silt, it filled half of the hose. As often happens, the episode ended without a conclusion although it was a realistic task to remove the silt in some other way as far as I know. If using the dredge was allowed despite of the protected species, then someone else could see this thing through by continuing where they left off. The owner of that property said in this episode that they don't want 'drilling' to be done anymore because there has been too many tragedies, but maybe they would allow further attempts to open the cave entrance. But I'm not encouraging anyone to bother the land owners without serious and honest intentions of taking it forward - they probably get enough cold calls as it is.
Edit: as to 'removing the silt in some other way', I would try a bigger dredge with more suction power, or just use an army shovel to dig the entrance even if it brings visibility to zero. It takes a month but so what - some progress is a good trade-off for no progress. There was also some carved rocks in the water before that were taken out. Scott identified them to be modern, being a geologist. Maybe some of you have better cost-effective ideas to remove or move the silt.
Honestly speaking I'm surprised that this has taken so long - what was the factor slowing down excavation/opening of that underwater cave so far? Are the land owners too selective and restricting in who they let to attempt opening the underwater cavern or is this particular lead not credible enough to motivate people? So far I've thought it was about the species protection laws, but then they took out that dredge all of a sudden...
I accidentally posted this to wrong thread, has nothing to do with Victorio Peak, sorry.
Wolter explains some things in his blog. I didn't notice the blog earlier and assumed the reason they didn't go further into the cave was the silt only, but it was in fact also because they ran out of filming time.
http://scottwolteranswers.blogspot.fi/2014/11/montezumas-treasure-guarded-by-snail.html