This 1964 ad by the Reno Harold’s Club Casino celebrates the “Washoe Causeway”- the bridge that crossed the wetlands on the north side of the lake to provide ore wagons access to the Ophir Quartz Mill from the Ophir Grade from Virginia City in the 1860s (See the article on Ophir below).
Since Virginia City did not have water or wood for milling ore in the new boomtown, it was hauled by wagon to Washoe Valley. An ore processing mill was built on the west side of the valley to take advantage of the abundant water and fuel. The causeway was built to span the wetlands for the wagons.
Remnants of the old causeway can still be found if one searches enough.
Harold’s Club was a great supporter of Western Nevada history and this site should create an article celebrating that! They had wonderful displays in the casino and produced books as well as these historically oriented ads periodically. Note: With my browser I can enlarge the ad enough to read it. Let me know if you have problems with this.