The link below is to an article on the Civil War in and around the Cherokee Neutral lands. Prior to the signing of the Cherokee-Confederate treaty, Stand Watie had already been commissioned by Ben McCulloch as a colonel and authorized to raise a battalion. He was instructed to operate outside the boundaries of the Cherokee Nation 'proper' (though the Neutral Lands were technically still part of the Cherokee Nation). It is possible that Watie and Thomas Livingston participated in raids with John Mathews in southern Kansas including the sacking of Humboldt in early September 1861. As shown in the article, some pre-war residents of the Neutral Lands are later found in Watie's regiments.

First, here is a report by McCulloch regarding Watie in southern Kansas.

OFFICIAL RECORDS: Series 1, vol 3, Part 1 (Wilson's Creek Campaign)
Page 691 Chapter X. CORRESPONDENCE, ETC.-CONFEDERATE.

Brig. Gen. Ben McCulloch to CSA Secr of War L.P. Walker, Sept. 2, 1861

You will see by the documents inclosed that the Cherokees have at last joined the South, and offered our Government a regiment. this, no doubt, was brought about by the battle of Oak Hills. I have, previous to this time, employed some of the Cherokees, under Colonel Stand Watie, to assist me in protecting the northern borders of the Cherokees from the inroads of the jayhawkers of Kansas. This they have effectually done, and at this time are on the Cherokee neutral lands in Kansas. Colonel Stand Watie belongs to the true Southern party, composed mostly of mixed bloods, and opposed to John Ross, and by whose course and influence Ross was induced to join the South. I hope our Government will continue this gallant man and true friend of our country in service, and attach him and his men (some 300) to my command. It might be well to give him a battalion separate from the Cherokee regiment under Colonel Drew. Colonel Drew's regiment will be mostly composed of full-bloods, whilst those with Colonel Stand Watie will be half-breeds, who are educated men, and good soldiers anywhere, in or out of the Nation. Having been left without instructions in many particulars, I have pursued the course I thought most beneficial to my country.

Here's Cheatham's article:

'If the Union Wins, We Won't Have Anything Left': The Rise and Fall of the Southern Cherokees of Kansas
Kansas History - Autumn 2007
(Vol. 30, No. 3)
Gary L. Cheatham

http://www.kshs.org/publicat/history/2007autumn_cheatham.pdf