Went here with husband and kids aged 11 and 8.
We were originally told at the visitor area that the road was closed but there was a hike of about a mile from the great forest museum. So, we parked and hiked out (easy walk) for about 1.5 before turning around when we saw a sign that said Moro Rock 4 miles, but looking back now, it may have said .4 miles. When we got back we saw the road was actually open so we drove right up to the parking lot and walked to the top of the rock.
So, the hike was great, and would highly recommend it. The walk to the top of Moro rock was worth it but...I was very nervous, especially with my 8 year old, I had a hand on her arm or collar the whole time. If it was rainy or slippery I would not have tried it. The views are just as good 50 steps up as if you go to the very top, so even if you are not physically able to do all the steps (300?) to the top, do what you can and enjoy the views.
It was 10 for a day pass to get into the park. There was construction going on, but the rangers in the entry booth or visitor center can help you time your drive.
If you own or manage Moro Rock, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.