Puppy + Rattlesnake, But Disaster Averted

Took my well-on-his-way-to-being-a-dog puppy for a short hike the other day. Stopped at the head of a trail that split off from the fire road. Not sure why I stopped--I think I was thinking about which way to go. Pup, on leash, kind of started poking around slightly off-trail to the right, down the small decline at the trail head. Even in the heat of the day, of course, there's considerable racket in the woods--frogs and bugs and whatnot making those SHHHH-SHHHH-SHHHH noises. Found myself listening pretty carefully to one of the prominent noises. Had the following thought:
Jeez, that [frog or bug or whatever] sure sounds a lot like a rattlesnake...
After a couple of seconds...
[SEMI-ARTICULATE REALIZATION HITS]
Look down, slightly down the trail...holy shit, there it is--about a 3' timber rattler, rattling away.
Puppy's still with me, but was looking and moving forward. Not close to striking range, but going in the wrong direction. Pull him back, everything's cool, but gave me a bit of a start.
   About 3' long, very light tan--about the coloration of a copperhead, actually. Black markings. Very gracile compared to the last one I saw, which was a big, almost totally black monster about as big around as my forearm, with a big 'ol honkin' head that looked as big a my hand. Also this rattle, as noted, was kind of a polite little rattle, compared to that last one which--though we (four of us) were in a smallish area enclosed by rocks, so that mattered--was absolutely ear-splitting and pretty scary. That last one, though, had gotten alarmed because we were all standing around gawking at him. He coiled up and cut loose. My friend's daughter clapped her hands over her ears it was so loud. This one, though...not all that effective as a warning was the way it struck me, anyway.
   Anyway, this one was stretched out, facing the trail, with its head only a couple inches from the edge of the trail. If I hadn't seen it--her, I'm guessing--that could have been bad. And that was the side of the trail the dog was walking on. I was mostly alarmed for the dog, who only weighs about 35 lbs. at this point.
   So I gawked at it for awhile and then we...decided to take a different trail lol. Immediately ran into a couple of bikers, and warned them--they wanted to see it. But by the time we got back, it was gone. One of them said he thinks he saw it moving through the grass just down from where I saw it, but I couldn't get a fix on it.
   Only later did I realize that, since I wasn't running, I had my pack on, and had my phone with me. Could have gotten some pics and video. Damn! That's the first one I've seen in probably five years, and the only one I've ever seen on that particular mountain, despite running there all the time. Bummer. But, on the bright side, no snake-bit puppy...