Gold prospected and flown to San Francisco to be minted

Gold prospectors digging and panning by shallow stream, man on horseback leading burros / men prospecting / closer shot man shoveling dirt into strainer rocked by another and one pours water in / man panning / man rocking strainer pouring water in, man carries pails of dirt / man pours bucket contents into strainer, another rocks it and pours water / man on horseback leading burros / men and horses walking toward plane in field / they reach plane with pilots standing by, words "Spirit of Mother Lode First Gold Bar from Mine to Mint by Air" on side; men on horseback move in front of camera / MS man pulls gold bar out of bag and copilot holds it up, pilot and another man near / pilots in cockpit, words "This is an International Biplane" on side, looks like man hands pilot bouquet / plane taking off in field, people on ground / plane in flight / VS plane landing in San Francisco / pilot hands bar to man in suit; they look into camera / woman comes up to pilot, kisses him and hands him large bouquet, man holding bar on other side / MS pilot, woman in fur-trimmed coat and man holding out bar / Note: exact month/day not known