Just an attempt to clear up some confusion.
Cayo mentioned the section between Reynold's (Landing) and Union Chutes in Littleton/Denver on the South Platte (aka "the dirty south").
Mattman mentioned a diversion dam below Reynold takeout, above Swallow Canyon, which is on the Arkansas, below Canon City and is actually spelled "Raynolds".
Imeyer mentioned a difficult dam to portage at the Portland cement plant above Florence. The Portland plant is below Florence and there is no dam.
I believe he means the CF&I dam above Florence that Formerflatlander is referring to.
And the Oil Creek diversion has always been runnable in a cat.
So I am aware of 4 access points in Canon City:
1) "Pink House" River right, used to be privately owned and leased to commercial raft companies, now is State Park public access ($7).
2) "Centennial Park" River Right below dam (chute on left) and below Oil Creek diversion, couple hundred yards below 1st Street Bridge.
3) "Train Station" River left, just below 4th Street Bridge and a wonderful play wave (Some commercial companies will claim this is a "commercial only" takeout, but there is no signs to support this and it is two blocks to a brew pub, so it is my standard takeout).
4) Park on River Right just below South Raynolds Ave two miles downstream of the Train Station (flat, but scenic with a few surf spots).
There is a bike trail that follows the river all the way thru Canon City.
Hope I did not add to the confusion