Denver Mint Proofs

None that I ever heard of and probably due to the altitude. The air is to thin to make a decent coin there anyway.
Possibly the government will not allow them to make any special coins since they had so much trouble putting D on a penny in 1922.
And then too they are known to cheat and put their D over the SanFranciso S at times. 1944D/S Cent. Of course the SanFran boys got even in 1946 with a S/D. In 1916 the Denver Mint spent so much time watching the Broncos playing football, they forgot to keep making Dimes so now the explanation for the low mintage.
NO, they just are not allowed to make proof coins.

The Denver proof question came up on another thread a few days ago. Here is my post from that thread:

Denver made proof strikes of the 1984 Olympics $10 gold piece. West Point and San Francisco proofs were also made. I bought one of the Denver coins, just because it was the only official Denver proof that had been produced.

I remember seeing a 1906-D Barber dime offered at auction as a "proof" presentation piece. Apparently Denver produced a few special coins when the mint opened in 1906. I don't know whether those would qualify as genuine proof strikings.

I see no reason why a brand new mint would not have made a some proof presentation pieces as part of a grand opening celebration. Considering the mintage figures for many of the early proofs, even a handful of presentation pieces should be seen as legitimate and worth mention.