I've done some hunting over the years to try and figure out whether the correct name was Pheasant or Pleasant. Most modern writings, in print and online, say Pleasant. I'm convinced that the original and correct name is Pheasant.

Peter Pitchlynn kept a diary of his travels to the new home of the Choctaw in the 1830s. In 1832, he refers to traveling up the Arkansas from Ft Smith to Pheasant Bluff.

See: http://www.missourireview.com/archives/bbarticle/found-text-series-peter-pitchlynn/

In 1837, it was proposed to abandon Ft Gibson and erect a new post closer to the Arkansas border. One of the sites proposed was Pheasant Bluff, "about six miles below the mouth of the Canadian".

See: https://books.google.com/books?id=dJMzAQAAMAAJ&pg=PA975&lpg=PA975&dq=%22pheasant+bluff%22+arkansas&source=bl&ots=gBXHKIJEoe&sig=PCyzyjwuqlLh5cvsWnOF-PZJBaQ&hl=en&sa=X&ei=9lqlVMbNOcbngwTDzILoAw&ved=0CDsQ6AEwBQ#v=onepage&q=%22pheasant%20bluff%22%20&f=false

In the Chronicles of Oklahoma, Muriel Wright give a list of landings on the Arkansas taken from the Arkansas Gazette which shows Pheasant Bluff.

see: http://digital.library.okstate.edu/Chronicles/v008/v008p065.html

In 1836, the the Baptist Missionary Magazine (reprinted in the Indian-Pioneer Papers) lists in Choctaw Nation, Arkansas District, "Pheasant Bluff Spring -- on Canadian river, 30 miles west of the Choctaw Agency. Missionary, Rev. Joseph Smedley, school-teacher". Oddly the subject index shows Pleasant but the text shows Pheasant.

However, in 1840, the Baptist General Convention reported Rev. Joseph Smedley and his wife "took up their residence at Pleasant Bluff Spring, on Canadian River, 30 miles west of the agency."

see: http://www.mocavo.com/History-of-American-Missions-to-the-Heathen-From-Their-Commencement-to-the-Present-Time-3/666181/559#559

In "Life Among the Choctaw Indians", published in 1860, Henry Benson refers to Pheasant Bluffs a number of times, including "The Honorable Nat Folsom was our district chief, a full-blooded Indian, uneducated, and able to converse but little in the English language. His residence was in the vicinity of Pheasant Bluffs, thirty miles from our mission. When I first saw him he was probably fifty years of age, large and well-developed; and, though considerably gray." See: http://www.accessgenealogy.com/native/distinguished-men.htm

In the ORs, the location is referred to as both Pheasant and Pleasant, depending on the writer. Cooper calls it Pheasant. Watie called it Pleasant.

It seems after the war the use of Pleasant became more common. I found a couple of references in the Indian-Pioneer Papers that refer to it as Pleasant. However, in the interview of Michial O. Ghormley, who served under Watie, he states "Forest trees and undergrowth were thick upon the heighth then known as Pheasant Bluff, the small town which has grown up
is now called Tamaha."

The oldest map I could find that shows a name for the location is the 1892 map of "Indian and Oklahoma Territories" which shows "Pheasant Bluff".

The OK Dept of Transporation map of Haskell County (1983) shows the creek name as Pheasant Creek.

The memoir of George Washington Greyson refers to the location as "Pleasant Bluff" in his autobiography 'A Creek Warrior for the Confederacy".

An 1870 survey of the Arkansas River done by the Corps of Engineers (Col. J.N. Macomb) shows the name "Pleasant Bluff".

"Adam's Directory of Points and Landings..." published in 1877 calls it Pleasant Bluff. See: http://www.forgottenbooks.com/readbook_text/Adams_Directory_of_Points_and_Landings_on_Rivers_and_Bayous_in_the_1000850946/193