In 1910 he supported Francisco Madero in his struggle against Porfirio Díaz and eventually joined Felipe Neri and Amador Salazar in forming the Zapatista agrarian movement in Morelos.

[2] After Zapata broke with Madero, Otilio Montaño remained in Morelos and in November 1911, together with Emiliano, co-authored the famous Plan of Ayala.

[4] Subsequent to Victoriano Huerta's coup against Madero, Montaño fought against Huerta and eventually became a member of the Zapatista ruling military junta, which was presided over by Emiliano Zapata and also included Eufemio Zapata, Genovevo de la O, Felipe Neri, Amador Salazar, and Manuel Palafox (who acted as the secretary).

[5] In December 1914, Montaño accompanied Zapata to the first meeting with Pancho Villa at Xochimilco where he gave the welcoming speech and introduced the two jefes to each other.

Although he vigorously denied the charges, influential Zapatistas including Manuel Palafox and Antonio Díaz Soto y Gama argued strongly that he was in fact guilty.