I go there all the time. 1 entrance is from the wildlife viewing platform below shadow mt dam. Normally you go towards the big red barn and take a left across the bridge. The sign says no dogs,since it's technically RMNP. If you go past the barn and stay on the right side of the river you are OK. The east side is a much better path and goes into better fishing,but it's off limits to dogs. Although I've had mine in there and had no trouble. You can also get to Columbine bay from the roaring fork campground trailhead. It over by arapaho bay. 5 mile hike to the Twin Creek Inlet(good fishing). Dogs are OK.