got our ballots Saturday still studying the propositions and amendments

receive by mail, use drop box

How does the state of Colorado know it was actually you who made the selections and put it in the Dropbox?

Mail in voting by definition has a paper trail
Some same day voting doesn't

Checks and recounts have shown mail-in to be super reliable
In fact... all voting has been shown to be super reliable
Trump demanded many recounts and dozens of frivolous lawsuits and turned up bupkis
Cyber Ninjas ultra partizan AZ recount found over 100 more votes for Biden
That must have hurt  

AZ has a tracking system that you can call or use a QR code to know where and when your own vote is and when it is counted
Mail-in has been happening here since the 90's
They got this down, but you can count on Trump to create chaos when he loses
Mark Kelly is winning, Kari Lake is losing yuge against Gallego, we have a Dem Governor and Trump will still expect to win

Kamala will win the swing states and maybe even Florida
Texas will be close... Cruz may lose as well

... and Trump is inexplicably campaigning in California and New York
Go figure
He's not even trying to win... he's planning to steal

How does the state of Colorado know it was actually you who made the selections and put it in the Dropbox?

 They don't.  It is plausible that any Colorado voter could intercept another's, cast votes, replicate their signature and return the ballot.  This is an opinion for those incapable of understanding what an opinion is.

 The problem is the volume needed and the spread.  For instance if I wanted to turn in 100 votes myself I would need to intercept 100 pieces of mail, from 100 humans that I already know will not vote, or care if they get a ballot and request another.  I would then need to match their signatures held in digital files.  This is an opinion.

 Surprisingly the signature thing is hard to beat, we among 3 other companies tried multiple times around 2006 - 2007.

 I would then need to turn those in in a sporadic non-pattern method near locations they would normally do this.  I would need to avoid the USPS as the sudden influx would trigger an alert.  

 My opinion is that it's doable for sure.  The biggest problem is securing ballots from people that do not care in my opinion.  It's not all that easy would be my opinion on this matter.

 This post has been an opinion.