Why does Project Blue Book get mentioned in "Twin Peaks"?

No more strange than the series itself.

I only saw the first two seasons of Twin Peaks and read The Secret Diary of Laura Palmer. Not the later series or movies,

Many things in the series fit some kind of dream logic, and/or were put in for ambient, artistic, or intuitive effect. Things seemed to match or correlate or connect that may or may not have, but sometimes led to revealing a clue later on, or some information gained later on traced back to the false lead. Facts and hard evidence were there, but so much of it seemed to move beyond the empirical. facts.

In the original series, Leo Johnson and Jacques Renault are suspected, but there was a third man who had sex with Laura Palmer that night she was killed—and from a dream, agent Cooper learns from information given by a one-armed man named Mike about himself and someone named Bob. Names which coincide with boys Laura knew in high school.

Coincidentally, they do find a one-armed man named Mike, who knows someone named Bob, a veterinarian, The one-armed man and the veterinarian turn out to NOT be the BOB and Mike from Cooper’s dream, but the veterinarian’s files trace a bird named Waldo back to Jacques Renault.

As with Stephen King, there IS an underlying connection to everything, but it is buried so deep in intuition and dream logic, that its best to enjoy from the perspective of a surreal dream—beautiful but with a sense of dread and foreboding just beyond what can be known.

I know I probably didn’t explain anything you didn’t already know. But clues in Twin Peaks are rarely understood by their literal reason for being in the plot.

Your question intrigued me enough to watch the first two seasons again, and I did it on Netflix in just two nights. It has been 29 – 30 years since I saw it last. I remembered a lot more than I thought I would, and watching it again tightened a lot of loose open questions. Wow!

It seems that the first season focused more on the ambiance of the fear of the woods, the dark, the primal wilderness, and what’s out there just beyond the flashlight beam. Of some dark presence in the vast wilderness, and its correlation somehow to fear and amprehension involving secret cults, forbidden sex and domination,

The second season still was exploring this theme but added the extraterrestrial X-files type element. Both Windham Earl and Col. Briggs had ties to Project Bluebook, the White Lodge and Black Lodge had more stellar implications. It wasn’t really U.F.Os as much as it was about the interconnectedness with something totally alien and cosmic and invasive. Something you want to explore because its fascinating but delving into it is delving into something totally alien and eldritch.

I’ve noticed that there has been a lot more Twin Peaks information on Wiki, and several other movies and a new series. I plan on getting into it now—but sometimes I think it is best to leave it a mystery and draw one’s own conclusions, or draw no conclusions.