Grizzly Mountain is an easy drive-up summit about 9 miles west of Prineville. The views are great and the road passable in a passenger vehicle - perhaps slowly in the rocky places. 

Head 9 miles west of Prineville on Highway 26 to Grizzly Mountain Road. Note that this is a Crook County Road (ftp://share.co.crook.or.us/RoadAtlas/30k/1315SW_M.pdf), and any "Private Property" signs posted on County Speed Limit signs don't really make any sense. The road is wide and well graded gravel much of the way, leaving some sections to rocky and rough and a bit steep. It's about 4 miles to the top where you'll find about ten RF sites of various kinds. These RF sites will likely make your 2m and 70cm HT useless - my Yaesu VX-8G was almost fully blocked on both bands - I only heard smatterings of responses to my CQ a few times - I apologized to the callers and gave up. Using a poor antenna might help, or finding a spot still in the AZ but with weaker RF (let me know where it is).

HF also has some RF noise from the sites with about S3 on 20m but turning off the KX3 preamp helped and all SSB Chasers were easily readable.