The genealogy link I posted earlier does not look to be entirely accurate. Any current descendants of Reagan would need to have professional genealogy work done or at least study up themselves on proper genealogical methods. And definitely always double check any genealogy work I lay out.
Looks like Harley Reagan's maternal grandfather was enrolled, his mother was not.
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Claude Harley Reagan
Texas, Birth Index
Name Claude Harley Reagan
Event Type Birth
Event Date 09 Jun 1941
Event Place Lynn, Texas
Gender Male
Father's Name Jno Reagan Reagan
Mother's Name Ida Mae Raper
https://familysearch.org/ark:/61903/1:1:V8WP-8FKClaude Henry Reagan's parents were Johnny Jefferson Reagan and Ida Mae Raper.
Name Ida Mae Raper
Birth Date 11 Apr 1924
Birth Place Hale Center, Hale
Father William Harley Raper
Mother Johnnie Edmond King
(Ancestry.com. Texas, Birth Certificates, 1903-1932 [database on-line]. Provo, UT, USA: Ancestry.com Operations, Inc., 2013.
Original data: Texas Department of State Health Services. Texas Birth Certificates, 1903–1932. iArchives, Orem, Utah.)
Ida Mae Raper's father applied for enrollment in the Eastern Band of Cherokee Indians of North Carolina. He was accepted, his children were not.
Cherokee Indian Agency
Cherokee, North Carolina
April 30, 1928
Mr. Harley Raper
Hale Center, Texas
Dear Sir:
You are hereby notified that the Eastern Cherokee Enrolling Commission has decided to recommend your enrollment with the Eastern Band of Cherokee Indians of North Carolina under the Act of June 4, 1924. Your children have been rejected on the ground that they were born separate and apart from the Eastern Band of your marriage to a white woman, and they have never had any association with nor recognition by the said Band as members thereof.
(Ancestry.com. U.S., Cherokee Baker Roll and Records, 1924-1929 [database on-line]. Provo, UT, USA: Ancestry.com Operations, Inc., 2013.
Original data: The 1928 Baker Roll and Records of the Eastern Cherokee Enrolling Commission, 1924–1929. Microfilm M2104, 69 rolls. Records of the Bureau of Indian Affairs, Record Group 75. The National Archives and Records Administration, Washington, D.C.)
William Harley Raper's claim was through his father Barry Bruce Raper/ Berry B.B. Raper, grandfather Alexander Raper, paternal grandmother Catherine McDaniel.
In the 1931 Eastern Cherokee census roll Berry B. B. Raper is listed as 1/4 N.C. Cherokee.
From Berry B.B. Raper's (Claude Harley Reagan's great grandfather) application:
I know that my father, his sisters and brothers claimed their relation to the Eastern Band Cherokee Indians, visited them and attended their councils and elections, and it is common history that the older ones, older than I, made contributions to their buying property and making settlements about disputed lines of their lands. I know very little personally execpt by contact, conversations and history.
I have attended their councils, visited them in person many a time, and after I was grown and married they visited my own home and I visited them. I have twice participated in the distribution of money apportioned to Eastern Band Cherokee.
(same source as above)
In Berry B.B. Raper's application he stated he was 1/8 Eastern Cherokee.