Firstly, let's calculate the total distance that Maribel has, so far, ridden on her bicycle. We find this by adding the distance she rode from her home to the park to the distance she rode from the park to the school. This sums up to 60 miles.
Now, to find out the remaining distance Maribel needs to ride to reach the post office, we subtract the distance she has already ridden from the total length of the bicycle path.
So, the remaining distance Maribel will need to ride to reach the post office equals 134 miles (total path length) minus 60 miles (distance already ridden), which equals 74 miles.
Hence, Maribel still needs to ride 74 more miles to reach the post office.
Answerr: Maribel still needs to ride 74 more miles to reach the post office.