Sorry for the lack of clarity. I started at the safeway in the downtown area, and walked to the walmart on the other side of town, in the opposite direction of the school zones, which end at their farthest approximately a half mile before safeway on the main stretch of State Street in downtown Ukiah. When I say the police were helpful, I spoke on the phone with a Sgt. Baartz, Ukiah PD, prior to arriving in Ukiah. He appeared to be very well versed on open carry, and was kind enough to alert his dispatchers that someone would be UOCing in the downtown area. He also notified Mendocino County Sheriff and CHP, all of whom passed me at least once while I was strolling about with my dog, and did not stop to perform a 12031(e) inspection. Approximately 4 hours after arriving in Ukiah, I left without any problems. Hence, I found it to be an overall good experience.
Prior to my trip to Ukiah, with help from the Ukiah School District website, google maps, and google search, I printed a map of the downtown area with each school and its accompanying 1000' radius drawn in a circle of blue, making it very easy to see where the school zones ended in relation to my position and choice of venues to patronize.
Best
-Max