A number of us were looking and listening this morning in hopes of finding the Black-chinned Sparrow reported by others. Steve Buffi and I arrived about 8:30 and Sandy Ritchie was already there with others.
Steve and I started lower than the group and Sandy joined us. We then moved higher when we were told that it had been seen at the higher corner. Finally, about 10:30 we started hearing and then found a male Black-chinned Sparrow. Steve's eBird reports are here:
The Bell's Sparrow never sang for us, but Sandy and Steve had one lower down the road, and a bunch of us had one fly and land right below our upper location along the road.
As others have written, this is maybe half-a-mile downhill from the entry kiosk. Patience was required.
Hugh B. Harvey