It is important to note that this section of the river can be difficult to paddle during much of the year due to low water and should only be attempted when the Mountain Brook USGS gauge indicates a flow of at least 100 CFS. After you enter the river, you will pass under the I-20 bridge at just .2 of a mile. At .9 of a mile you will encounter a bend in the river with many large rocks, which you should be careful going through. At the next bend to the left, there are a number of low rocks coming out from the left bank that create a rapid. Stay to the right and run the chute, which is about a 2' drop. If the water is up about a foot through here, be very careful. At mile 3.8 a creek enters the river on the right and just past the next bend to the left, you will encounter a shoal with a total drop of 3 feet, which you should take down the middle of the river. At mile 4.8 you will encounter another set of shoals with an 18" drop followed by some islands. This is the historical location of Grants Mill. After you pass under the Grants Mill Rd. bridge just past the islands, the Grants Mill access will be on your right. There is an old concrete slab that once served as the only paddling access. However, we recommend using the new access located just 30 yards further downstream on your right. You will find the new access to be much easier to use.