The Arkansas River arises in Colorado and still has that name when it flows into the Mississippi. It's the only Colorado River I know of that flows directly into the Mississippi.
The Platte (both the North and South) arise in Colorado and join in Nebraska before flowing into the Missouri, which then joins the Mississippi.
The Republican and Smoky Hill Rivers join in Kansas to form the Kansas River, which then flows into the Missouri and thence the Mississippi.
All other significant Colorado rivers that don't join one of the above either wind up in the Rio Grande or the Colorado River, neither of which ever joins the Mississippi.
south
The Missouri does, the Colorado does not. It empties instead into the Sea of Cortez.
The two major rivers in the western region of the United States are the Missouri and Colorado rivers.
youthful stream
there are no rivers flowing in to the mountains however many flow out --Colorado-- SouthPlatte--RioGrande--Laramie--
The Colorado River.
The Sea of Cortez.
Mississippi, Missouri, Colorado
these are the peninsular rivers:-1)mahanadi2)tapi2)kirshna3)kaverietc.
COlorado and Hawaii
Ohio and Colorado
The two major rivers that flow into the Mississippi river are the Missouri river and Ohio River.