Big South Poudre Hiking

I was thinking of doing a hiking trip along the Big South section of the Poudre. I would like to hike from near the put-in to the take out but noticed that the trail is on river left from the top down to Peterson Lake then it is on river right down to the take out. Does anyone know if it is possible to cross the river around Peterson Lake? As an alternative, we could just hike around the upper section above Peterson Lake. I was thinking of 2 nights but camping the first night on Friday after work so we would try to camp near Starter Fluid. Has anyone hiked the trails up there and know if they are well marked or easy to follow down to Peterson Lake? Also, has anyone crossed the bridge above Starter Fluid to head up stream and if so if it is worth venturing up that way? Thanks!