Other than Carter Caves in KY, do you encounter a lot of bridges that aren't man made?
Maybe a couple of cave symbols on either side of the Jeep trail?
I've mapped these in schools before as two tunnel ends. So none of your options.
Looks like trip hazzard to me, but I don't think there is a symbol for that.
tRicky: on orienteering maps two tunnel ends back to back equals one bridge (but I'm guessing you know that).
It is a bridge. Sorry my ISOM file was temporarily unavailable and I don't know symbols by heart so I had assumed for some reason that he meant the bridge symbol as in the solid black line across a creek rather than the tunnel symbol. The perils of replying whilst at work!
So yes, #2 (though I had been thinking of two Vs, which apparently doesn't exist and neither does the solid black line across a creek, which seems to be a MTBO symbol).
I would have said #2 on the basis that it's functionally a footbridge and it's way too big to just be mapped as a footpath, but:
Looks like trip hazzard to me, but I don't think there is a symbol for that.
Since Richard is the current local expert on trip hazards I might have to agree with him.
ISOM?
Footpath (or vehicle track, hard to tell) with the dash crossing the stream to show there's a little bridge/crossing point.
Depends if you have a control inside the tunnel.
Re-reading ISOM:
If it is not possible to get through a tunnel (or under a bridge), it shall be
omitted.
Do we need to differentiate between "possible" and "a good idea"? :)
I think Canadian (Jeff T), makes the most important point,
The first priority is to show the trail (and stream) situation, accurately, with the proper grades (agreed hard to tell), angles, and junctions(?), with no displacement or exaggeration.
As long as no dash break occurs over the stream, a bridge is implied.
The rest depends on context. In different settings, I could probably agree to many different options.
However in this setting, assuming a normal scale, there doesn't appear to be space for either 512 or 531 (large cumbersome symbols), without serious displacement, clutter, or touching.
There might be space for two caves, but I think two min length tagless cliffs, would be equally applicable, whichever makes the cleanest picture.
Even these options might be cluttering so no-additional-symbol should also be an option.
BTW, rotatable black v's and single black dash bridges are still in the ISOM 2017-2 (last rev 4/7/22) that I just looked at.
Pity you left your geologists hammer at home, sherpes.