I am trying to change the visibility range on a map I'm making. The map is surrounded on all sides by a large canyon wall I made in XSI. But from the inside of the map, you can barely see any of it. I cranked up (maybe, I don't know how much I actually did) the view distance in the SKY file:
Am i doing this right?

FarSceneRange is for the background area of a map, from what I gather of psych0fred's posts on the sky file. Setting it to 9000, 9000 is probably not what you want to do here, for several reasons, and should probably be set back to something reasonable. You should also eliminate the duplicate FarSceneRange line.

Try playing with the ingame video sliders for view distance and LOD distance to see if you can get it from there before you play with the sky file. The sky values are linked to the view distance slider (and there's a bit that suggests to me the LOD slider has an effect as well), so you should only really need to alter the sky file if you can't get the view distance you need from the ingame video options. If you absolutely need to, try increasing the values on the NearSceneRange a little until you can see the object. Keep in mind doing this does increase the amount of objects that have to be rendered, thus your map will take up more memory as a result.

Also, your midrange is 40 meters (80, 120), which doesn't seem like a good idea since you're having both high and low res models rendered in that range at the same time.

Also did you make a lowres model of your canyon walls?
This would also help in keeping something in view as you move away.