I've progressed in my research since that message was posted:
Husband: Joseph Hayden Routh, Sr.
Born: April 2, 1841 Barry County, Missouri
Married: August 19, 1865 Fayette County, Texas
Died: June 17, 1923 Ballinger, Runnels County, Texas
Buried: 21 Jun 1923 Place: Evergreen Cemetery, Ballinger, Runnels, Texas
Parents:Dr. Kenzie Routh and Amanda Melvina Murrell
Wife: Amanda Elizabeth O'Daniel
Born: October 6, 1847 Plum Grove, Fayette County, TX
Died: February 26, 1893 Ballinger, Runnels County, Texas
Buried: Evergreen Cemetery, Runnels Co.
Parents:James O'Daniel and Elizabeth Alice Scallorn
1) M James Kensington Routh
Born: November 28, 1866 Plum Grove, Fayette County, TX
Died: January 9, 1874 Plum Grove, Fayette County, Texas
2) M William Abercrombie Routh
Born: March 13, 1868 Plum Grove, Fayette County, Texas
Died: May 6, 1872 Plum Grove, Fayette County, Texas
3) F Emma Amanda Melvina Routh
Born: March 2, 1870 Plum Grove, Fayette County, Texas
Spouse: William Perkins Nash, Sr.
Married: June 5, 1890 Runnels County, Texas
Died: May 14, 1962 Brownwood, Brown County, Texas
4) M Joseph Hayden Routh, Jr.
Born: April 30, 1872 Plum Grove, Fayette County, Texas
Spouse: Greola Jane Ballou/Bolen
Married: November 18, 1893 Ballinger, Runnels County, Texas
Died: December 24, 1915 Ballinger, Runnels County, Texas
5) F Josie Bradshaw Routh
Born: November 28, 1874 Plum Grove, Fayette County, Texas
Spouse: Robert Lee Maddox
Married: April 20, 1898 Runnels County, Texas
Died: January 10, 1931 Ballinger, Runnels County, Texas
The probate case was actually dated July 14, 1916 and concerned the children of Joseph Hayden Routh, Jr. He died in Runnels County on 24 December 1915. Although I haven't yet obtained it, it concerned Kathryn, Nell Marie, and Will Edwin Routh who were minors at the time of his death.
It is most likely that the post card was sent to Mrs. Emma "Amanda Melvina" Routh as it is dated 1908. I've speculated that she was named her paternal grandmother, Amanda Melvina Murrell.
Muldoon is a town in southwestern Fayette County, Texas 10 miles north of Flatonia, and 16 miles southwest of La Grange.
Since it was originally addressed to her in Oakland, Texas then forwarded to Muldoon the possibility exists that perhaps Mrs. A.M. Routh was previously residing in Oakland around that time.
There are six communities named Oakland active in 1908. I think the most probable are these two:
The Oakland in Colorado County is just southwest of the intersection of Farm roads 532 and 2144, on the Lavaca county line eight miles south of Weimar in northwest Colorado County. It is on a site originally granted to James Bowie. As early as 1844 the community, then called Prairie Point, had a store on the stage line between Columbus and Gonzales. In 1884 the town had 200 inhabitants, a public school, three general stores, a saloon, a steam cotton gin, two churches, and grist and saw mills. In 1900 Oakland had a population of 264, and in 1904 the community had one school with sixty-five white pupils and another school with eighty-one black pupils.
The Oakland located Brazoria County is one mile west of Freeport and one mile north of State Highway 36 in south central Brazoria County. Oakland was the name of the plantation of Henry William Munson, who came to the county in 1828 and purchased land from Stephen F. Austin. State highway maps of 1936 showed a church and school at the site, but in 1974 only St. Joseph Church, an adjacent cemetery, and scattered dwellings remained.
Of the two above, I think it most likely she was at one time, located in Oakland, Colorado County. More research is required, however.
There were also towns named Oakland in Cherokee, Houston, Hopkins and Van Zandt Counties.
My father's name isn't A.M. Routh - perhaps I didn't make that clear in the original post. My relation to the Routh family is through my paternal grandmother.
Appreciate your response and interest.