Mitchell helped establish both the Baca House and Bloom Mansion as historic sites and are now both parts of the Trinidad History Museum.

He was a member of the 166th Depot Brigade of the Regular Army National Guard Enlisted Reserve Corps Regiment.

[5] In the fall of 1925, Mitchell followed friend and fellow artist Harold von Schmidt[7] to New York City to study at the Grand Central School of Art under teacher Harvey Dunn.

[7] In 1935, Mitchell started creating artwork for book covers, including that of The Spur of Time, The End of Black Jack, and The Spider Web Trail for the publishing house Houghton Mifflin Company.

[7][10] He collected items that a cowboy would use, like saddles, camp coffee pots, Indian blankets, and pottery for his works of art.

[5] He depicted the lives of cowboys, cowgirls, and Native Americans in the prairies and plains of northern New Mexico and southern Colorado.

His portrayed battles of Native Americans, people traveling along the Santa Fe Trail, with images of notable western men like Kit Carson and Billy the Kid.

[4] Governor Stephen McNichols announced the selection of the emblem to be used on souveniors and promotional items approved by the Centennial Commission.

[14] Mitchell helped establish both the Baca House[15] and Bloom Mansion[16] as historic sites and are now both parts of the Trinidad History Museum.

[2] In 1962, Mitchell received the community's Outstanding Service Award for his "foresight and leadership in the preservation and restoration of two historically and architecturally important landmarks in Trinidad.

Following Mitchell's death, his sister, Ethel "Tot" Mitchell-Erickson, decided to donate her and her brother's western art and historical memorabilia collection to a museum.