The gateway to Hartnet Road and Cathedral Valley. Cross at an angle (you can see the exit spot if you follow the tire tracks along an imaginary line across the river).
I have read that the crossing is often only ankle-deep, but I have never found it that low throughout, though that does not mean it never is. Once, when crossing from the "civilized" side to the "wild" side, my car stalled at the far side. Luckily, it had enough momentum to roll clear of the water, and I got it started again.
Needless to say, check the water depth first. High clearance is essential for this ford, and 4wd is good as well.