How to read/map mineral rights in lease

I am trying to see where my mineral rights are. I have mineral rights in the Fayetteville Shale in Arkansas. In the lease my father signed, he has since passed away, it states the following:

N/2 NEI4 & SE/4 NEI4 of Section 11, Township 8 North, Range 18 West, LESS AND EXCEPT that part described as beginning at the SE corner of said section, thence West 9 rods and 1 yard; thence North 30 rods; thence Northeastwardly 9 rods and 1 yard; thence South 35
rods to the FOB.

NW/4 NW/4 of Section 12, Township 8 North, Range 18 West, LESS AND EXCEPT that part described as beginning at the SE corner; thence North 10.4 rods; thence South 67 degrees 45' West 27.9 rods; thence East 25.42 rods to the FOB. All that part of the SW/4 NW/4
described as beginning at the NW corner thence South 45 rods to a branch; thence with said branch in a Northeasterly direction to where the Atkins-Appleton Road crosses same; thence Northwesterly with said road about 18 rods; thence Northeasterly with another road to a
point in the North line of said SW/4 NW/4 25.42 rods West of the NE corner of said SW/4 NW/4; thence West 54.58 rods to the POB.

How would I go about mapping this out to see how much mineral rights I actually own?

Thanks in advance.

I found a site that got me pretty close, but had to study rods, chains, and what was the actual length of rods and chains in Arkansas at that time. Eventually went and walked the area property, found the branch, but it wasn't until I found who the present owner of the land was and was able to go to county records and determine acreage then. Once leased or especially once receiving royalties, companies will have to get pretty close before checks go out. Maybe you want to participate or claim not to lease/participate, you may still be at driller mercy. I will see if I still have that site info on computer. google search "how to find acreage by using rods and chains, survey, plat, etc" think the site I found was free for 30 days or something, didn't stay with it. by following the directions, which I didn't really understand much, my lines crossed a couple of times

2 things you could do if your just wanting to know your net mineral acres. Call the leasee, they will normally tell you if you are the owner. Also, call the county assessor, they will be able to help you by looking at the surface acres but the first option is the best method. Or you could do it the hard way by figuring it yourself, since they are broken up tracts it is a lot more difficult to figure based on dimensions.