Is that San Antonia creek your talking about Rick, the one that comes down the canyon from the Mt Baldy village all the way to the dam on the north side of Upland. I grew up about a quarter mile south of that dam, lived on 24th street, west of Mountain. We used to go hiking up San Antonio creek, and used to camp in the old abandoned buildings of a Boy Scout retreat, up in the canyon, where segments of the old Mt Baldy Road were still intact. We used to catch trout in the pools of San Antonio creek with our hands. Funny one day me and my friend came upon two gals skinny dippin. Us young guys had never seen nothin like that, so we worked our way downstream towards them acting like we hadn't seen them. They ended up talking to us for a while and we were in Hog Heaven. Funny that I should end up many years later being a fan of skinny dippin myself :-) In 1969 there was massive flooding in San Antonio creek, and it almost filled the San Antonio dam all the way to the top. Didn't make it over the spillway but it was pretty close. The flooding washed through the Mt Baldy trout pond ( ponds you payed to fish in ) and it washed all those big trout down into the dam. Late that summer my friends and I would go up behind the dam to fish for the trout. Finally the water go so low that one day we were up there the many trout started getting sluggish from lack of oxygen and water that was too warm for them. Man we got a haul of trout that day, carrying our catch back over the dam in a big black bag. I remember when that flooding was happening, even though we lived down below that big dam, we could here the roaring of San Antonia creek clear from the other side. The flooding washed out the bridge near the ranger station which is a few miles up stream from the dam. Also not to far from that ranger station there was a side canyon that came down the hills to intersect with San Antonio creek. The side canyon was named Stodard Canyon, and we would hike way back up in it to waterfalls, and catch snakes along the way. So many fun times as a kid hiking all over that area :-)
