Leona Heights Neighborhood Newsby Gordon Laverty |
In the past several columns, we have looked at the mining activities of the late 1800s and early 1900s in the Leona Heights area. The impacts of these historic operations remain in the present and will affect the future. |
For example, the old mining activities had a dramatic effect upon the present Ridgemont as well as earlier developments when S. J. "Bud" Blair pointed out to city planners the location and extent of mining tunnels under the present Leona Greenbelt site. Earthmovers had to reconsider excavation strategies so that large underground "rooms" would not swallow the big equipment. One estimate of total ore removals from Leona Mine over its life would approximate the volume of the Kaiser Building in Oakland. Thousands of feet of tunnels connecting the
Leona and Alma Mines honeycomb the Greenbelt zone. Bud Blair declared before his death that he had in 1964 spoken to one old timer, now deceased, who had walked through the tunnels from Leona to Alma Mine. The old tunnels and adits (penetrations from the tunnels to daylight) pose a serious risk to developers along creeks in the region. Because Leona rhyolite is so pervious to infiltrating rain, in years of high rainfall the Leona mine tunnels fill with water and sometimes "pop" the closure plugs ordered by the city to prevent juvenile intrusion. When the plugs blow, torrents of water flow down Leona and other creeklets in an unusually dangerous fashion certainly enough to destroy poorly located homes if they are ever built. One visual leftover of the Leona Mine is the tailings pile on Leona Creek above Leona Street and near the end of McDonnell Avenue. The acid runoff from these diggings still affects stream flow sufficiently to cause a cleanup order by the Regional Water Quality Control Board. The argument as to who shall execute and pay for cleanup remains a problem and hinders the acquisition by the East Bay Regional Park District of the Leona Greenbelt. So the ghosts of our mining heritage continue to haunt us. If we uncover more history gems of the Leona Heights area, we will pass them along to you.
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