While LE was looking at BM, why couldn't FBI and CBI been doing this back a month ago?!
FBI and CBI don't usually do the tasks of community police. It would be very rare. FBI provided its evidence gathering team. This team is not the same as the FBI's case investigation or profiling units. Typically, all that FBI team does is help with electronic data, rapid subpoenas, analysis, and also, new kinds of digital data collection that are developed all the time. For example, once they know the apps on Suzanne's phone and on other phones of interest, the FBI knows a lot about the kind of data one can get from that app company. It's amazing how much data is stored on individuals by various apps (even just game apps, but most families have something they use besides Messenger and FB). Most people have apps that track them (and save all the data) more than they realize. I suspect that's the FBI's main role here.
CBI, OTOH, is more likely to have major bio-forensic capacity than little Chaffee County. Just the examination of the bike, the pollen, the dirt, etc is in their bailiwick and you'd want their expertise if you were LE.
Do you have much experience in following true crime? Because neither the FBI nor CBI has the kind of person power to, for example, add people to on-ground search teams, watch videos collected, or go door to door. Most counties find themselves strained by having to do this kind of thing and we're lucky that Salida is small enough (and the County seat - so more LE resources) for them to do this. It's what you'd expect a small town with a strong sense of compassion and pride to do.
The FBI and CBI are probably now in the shadows, as I have never seen FBI agents go door to door in anything other than issues involving federal crimes (which is what their on-ground teams are trained to do - not state level criminal case crimes). CBI does not, AFAIK, have its own extra personnel at the ready to do this either (nor does any other state bureau that I know of).
I've seen other local services help out if the matters are not too ticklish (Highway Patrol, police from another city in the same county).
Can you give an example of a missing person's case where the FBI or a state bureau did get involved in that way on the ground? Year end stats for missing persons in the US was 612,000 for 2018. Can you imagine the number of agents the federal government would have to employ if it decided to do door-to0-door canvasing in each and every one?
I think it's important to understand just how massive a problem this is (Missing Persons) and how some cases (Suzanne's, Barbara Thomas's, Gannon's) get more press (Suzanne more than Barbara), more attention on WS, etc.
But for every Suzanne there are hundreds of others gone missing with *no* FBI or state level involvement at all. That's a reason that so many of us are interesting in what's happening in Mayville and Salida.