Others in the Arkansas census records that may possibly be McElyea's, but due to the name perhaps being misunderstood by census workers, the spelling is different follow. They may or may not be McElyea's but I am including the indexes.
1850 Arkansas Census Index
McCauley,William 49,Nancy 29, William P.,Mary J.9, Martha 4,George H.2--NC/TN--dwg.158--Ouachita twp., Bradley Co.
McCaully,W.C. 40,Mary 30, Hiram 20, Frances 15, William 14, Sarah 12, Martha 9, Mary 3, --NC/NC--dwg.222--Marion twp.--White Co.
McCavley, George W. 37, Olivia 29, Mary 12, Nancy 10, William 8, Sarah A. 6, Leonard 4, John 2--TN/KY--dwg.54, Perry twp.--Johnson Co.
1860 Arkansas Census Index
On page 196 of the census index you will find several names either the spelling of McCauley, McCaulia,McCaulley, McCauly, McCawly, and McClay. You might want to check these names out if you are having trouble finding a relative. The spelling may be different than what you are looking for.
1850 Yell County Arkansas Census
page 483A, Line 31-38
Hiram McElyea 45 M Farmer N.C.
Sarah 44 F KY
Nancy J.. ? 18 F AL.
John B. 16 M Farmer AL.
Elizabeth P. 14 F. AL.
Oliva J. 13 F. AL.
Comodore 11 M AL.
William M.S. 9 M AL.
1860 Yell County Arkansas Census
page 1138, Line 9 – 14
Hiram McElyea 56 M Farmer North Carolina
Sarah 57 F Kentucky
Elizabeth 24 F Alabama
Oliver J. 22 M Alabama
Commodore P. 21 M Alabama
William Larkin 20 M. Alabama