At any rate the general gist of the "obstruction" claim seems to be him asking the NPS to give him stuff and they don't... either because he's asking for original master copies, or for information they simply don't have.... or some other reason... I don't have an exhaustive list. At any rate he seems to be making unreasonable requests of them, then accusing them of obstruction when they can't or won't comply.
This is one aspect on which I can speak accurately (I think). These are what I recall of his positions, I make no personal comment on their validity:
Paulides believes that the NPS
do have records, records that would amount
in toto to a near exhaustive list, but that they claim they do not, possibly, he speculates, because they are embarrassed by the slapdash nature of the investigations and searches that they conducted 'back in the day' (and he expresses some sympathy with them on this--the past being a different country and all that).
He further believes that the cost projected by the NPS to write-up and assemble their supposedly disparate files has been deliberately inflated to $1.4 million to prevent their having to release them.
More recently, he claims that his requests to film a documentary in (I think) Yellowstone have been mendaciously refused: that the NPS has been exploiting the Covid-19 lockdown and is being unreasonably meticulous with the process in order to to string-out the process so that the advance planning for his project becomes impracticable. One example of this he gives is that after paying the application fee (a few thousand dollars, I think) and completing a raft of paperwork, he was advised that the areas had asked to use were out of bounds. Rather than allowing him to 'transfer' the request to cover another area of the same park, they required that all the paperwork be resubmitted with another administrative fee and months more waiting. Specifically on this subject, he states that they are refusing to allow him to film in the non-public areas in which the disappearances actually took place (on the grounds that the terrain, flora and fauna look much the same elsewhere and he doesn't
need to be there), which while it obviates the costly need to visit Yellowstone at all, also stifles the attempt at authenticity for his film. He believes, I paraphrase, that their motivation here is to 'kill the story' as the public attention he has drawn to these cases (considerable, I think we'd agree) is bad for their institutional reputation.
I was going to supply links to the documents he has posted in support of these claims, but his website appears to be down at present.
There was also something about a conversation he or an associate had with somebody high-up in government (a former member of the administration, I think) that he believes supports his belief that such files as he wishes to view have already been assembled, but I'd have to check the details.