All of the gold that washes out of the Colorado is trapped by a dam a few miles East of Grand Junction and unless you can dig some old clay banks from old floods you might as well as forget about prospecting there. I am sure the State makes a killing on the gold that is deposited at the base of the dam each year, but if you are an amateur prospector just forget about it. I spent the day yesterday teaching my wife the layers and how gold is deposited and the way they set up the dam not one flake of gold will ever go downstream again through the Colorado River. I would like to be on the team that dredges that dam out every spring, it must be quite the haul.
There are some promising clay banks from past floods if you can get to them, but most are now park land and protected.
I will say this though, I saw some really promising veins of lode in Montrose County off HWY 141, I am just too crippled to try to work them. Here is the tip, you wont see them going South, it's when you head back to Grand Junction you start to spot them. It might be worth somebodies while to go and dry wash some of the old tailings from some of the old mines, there was a lot of color in the tailings.
and of course, get permission first......