California topo map in Oregon 550t question

[windtower]

I load the California topo map into my Oregon 550t's SD card. When I power on 550t, under Map info, there are totally 3 maps. First two are the same(California topo) and the last one is 100k topo. I run several tests. The 1st MUST be disabled and the second one must be enabled, of course, the 3rd one(toopo 100k) is enabled. As long as the 1st one enabled, I will see no street and no topo. Anyone has similar problem like this?

[-Oz-]

That map is weird.  It has contours in one file and the roads and water data in a second file.  You should have 1 and 2 enabled which will hide the 3rd one.

Most maps here will just have one map listed (Arizona topo for example).