I just spent a week in Southern Oregon. I was very surprised at the good
quality of CDMA coverage I received in relatively remote areas. I
believe that the CDMA came from U.S. Cellular. The GSM coverage was very
poor outside the cities, and I believe it came from Edge Wireless, an
AT&T affiliate (I brought along a prepaid phone that's on Cingular and
other GSM carriers).

At Oregon Caves National Monument (42.09806, -123.40722) I had a usable
digital signal on CDMA when I was outside, nothing on GSM. Same
situation at Lake of the Woods (42.37889, -122.21111). At Crater Lake
National Park (42.93, -122.15) I had good AMPS coverage (the part of the
park with digital coverage was not yet open due to snow). The AT&T web
site shows partner coverage for Oregon Caves and Lake of the Woods, but
no GSM coverage at all for the headquarters and lodge area of Crater
Lake National Park. It was rather amusing to be outside the lodge at
Crater Lake National park, watching people trying to make calls as
probably 2/3 of them couldn't because they either had GSM, or had a CDMA
phone that was all-digital. This is the kind of area where hopefully the
carriers will keep AMPS turned on after the mandate expires, since it's
AMPS or nothing.

I'm still on the old America's Choice Plan, and the phone showed
non-included roaming (steady rather than flashing display of "Extended
Network") so I am worried about the next bill. However last time this
happened to me, I was roaming on Cingular AMPS in Florida, and I didn't
get charged even though the phone indicated that I would be charged. My
niece was with us, and she has AC2, and was able to use digital with no
problem, so presumably Verizon does partner with whatever CDMA carriers
are in the area.

My kids had their PagePlus phones with them, and they had to enter the
phone numbers they were calling twice, indicating that they were roaming
at 2x the price that they would normally pay, but at least they had
coverage. This reinforces the suggestion that many people have made that
if you have GSM as your primary service, you should carry a prepaid
CDMA/AMPS phone when leaving urban areas.