Just saying that the government does, in fact, control information. The degree to which that is done is situational depending on a number of factors. The degree to which they do so regarding bigfoot is obviously a matter of debate.
I only have the following to go on.
1. From direct personal experience, they do exist.
2. The Army Corps of Engineers listed bigfoot as Northwestern fauna in the 1970's.
3. Based on 1 and 2 above, the government is aware of their existence.
4. The US government has not, since that Army Corps of Engineers publication, further acknowledged their existence.
5. On the other hand the government has not claimed that they do not exist. Recently, the stance has been that they have no proof or information regarding their existence.
6. FOIA requests, however, do turn up reports in various agency files, some from government employees regarding their existence.
7. There are, within the US, jurisdictions wherein bigfoot are protected by specific law, if not by name, then by description.
Is there a conspiracy? I haven't used that descriptor. When I have been in positions during my military career where I have been required to withhold information, I never looked at it as a conspiracy then. Just as information management.