...as "the Amphitheater range."
Pretty spartan page on the whole. No route page. Route info buried in the General section. Only four pictures (only one of which features Cow). I'd say the page isn't up to snuff.
I think it is the gates of heaven, but you may be right. See this photo: http://www.summitpost.org/images/original/349350.JPG
The Hot Springs Pool is below this high precipice. There is a road going up that hill, probably where the new trailhead starts. Did you hike this thing?
No it is actually bridge of heaven. The main trail head is of off horsethief trail. I have heard that you could access it from in town on old horsethief, however I have also heard that there was a private mining claim that closed it off. Here is a link to a map from Ouray trails
http://www.ouraytrails.org/trails06.html#horse as well as an old discussion on old horsethief trail http://www.ouraytrails.org/trails06.html#horseold
FWIW I have never seen anyone come up via old horsethief. I have not tried it but it looks you could access the area from Chief Ouray mine area. There are several good overlooks in the area from the picture you have. The blowout is up there as well as an overlook where old horsethief and horsethief should meet. A road leads to the blowout. There is also a house perched high on a ledge up there.