Yesterday i wathced fwwm first time,and can somebody tell a answer?

Here you go:

http://www.2000revue.com/community/topic.cfm?topicid=4068

Not definitively, no.

The Agent Desmond part was something that was put together when Kyle wouldn't give his full participation to FWWM. The disappearance was written in so Cooper could take over the case. Remember in the pilot, he said he investigated the Teresa Banks murder.

Let's see... he takes the ring from a mound of dirt, BOB left a mound of dirt with Laura's necklace. Cooper eventually disappears (well, the good Cooper does) and Agent Jeffries also disappeared.  It's got to be Lodge related.

EDIT: that was the short version of the thread mr. s linked to

I assume that Chet Desmond ended up in the Black Lodge somehow when he found the green ring under the trailer

He took the ring, became invisible and dropped it in Mount St. Helens.

He took the ring, became invisible and dropped it in Mount St. Helens.

 He saved the townsfolk from Sauron, who sent the Tremonds after Desmond.

 
 Remember in the pilot, he said he investigated the Teresa Banks murder.  

The pilot leaves this implied, perhaps, but I don't believe it ever comes directly out to state that Cooper was the investigator for the Banks murder.

 
 Remember in the pilot, he said he investigated the Teresa Banks murder.  

The pilot leaves this implied, perhaps, but I don't believe it ever comes directly out to state that Cooper was the investigator for the Banks murder.
 True. And he seems awfully jolly about the trees for it to have been his second time in the area.

And he seems awfully jolly about the trees for it to have been his second time in the area.

 I dunno.  It seems that there are several dozen return visitors with that same look come late July every year.