OIL DISCOVERY MADE IN POT holles DI STRICT OF COLORADO RIVER san diego cal july 23 there is much excitement among the miners in the eastern part of this county and the residents ot yuma over the discovery of what Is believed to be a bed of oil in the pot holes district of the colorado river about fifteen miles north otsuma ot Tuma A rush was made for the scene of the discovery and a scramble for land the belt became so that some of the first locators were compelled to use rifles in protecting their rights