Can I rent a GPS from national? I have been advised on tripadvisor to buy/bring a GPS. I am traveling the gorge, down to bend, then Crater Lake, then down to Gold beach then up the coast back to Portland.

Yes they Rent GPS Enterprise and Alamo Rent A Car also Rent GPS

Be aware that Crater Lake has VERY limited visibility due to the fires. We were just there Monday July 30 and couldn't see the surface of the water in most places. Also, we used our cell phones instead of paying extra for the GPS.

They will be more than happy to rent a GPS to you. That's a beautiful drive you're taking...