Lilsalmon, here's an easy way to get to Hayden Bridge from Armitage Park. Turn onto Mckenzie View Dr that's on the north end of the bridge on Coburg Rd. Follow this road to Hill Rd. Turn right at Hill Rd and drive until you come to an intersection with a light. Turn right onto Marcola Rd. You will see a small store on your left and then the river this is Hayden Bridge. On the store side there's some great looking water. I've see people fish there all the time. There's free parking if you can find a spot along the road or you can pay park at the boat ramp parking off of Hayden Bridge Rd on the west side of the bridge on your right. Also if you drive up the road about a quarter mile there's free parking on your left. At the back of that parking lot you will see a gated road that will take you to some good water also. Here's a google link.
Google Maps