Before getting too far into this, have a look at the section of a 1905 Rand-McNally map above. On the left is Palo Pinto County; near the center of the northern edge is a place called Christian, where a young doctor I. M. Howard practiced in the early 1900s. He also practiced in several nearby communities: Graford, just below Christian about five miles to the south; Oran, about five miles to the east; Whitt, just over the Parker County line to the east of Oran (the little circle next to the vertical “Creek”); and Peaster, Robert E. Howard’s birthplace, about ten miles southeast of Whitt and 40 miles northwest of Fort Worth (off the map to the right). The distance from Christian to Peaster is 25 miles, as the crow flies. On today’s roads, interested travelers can tour all of these tiny towns in one or two hours.
[For a peek at Dr. Howard’s movements before the 1900s, look here.]
After a brief stint in the Indian Territory, where he had most likely gone to help out his favorite sister, Willie, Dr. Isaac Mordecai Howard (IMH) returned to Texas, where his Physician’s Certificate was filed for record in Palo Pinto County on January 8, 1902. Polk’s Medical Register and Directory for 1902 has him in both Petersburg, Indian Territory (which I assume is a holdover from a previous notification), and Graford, in Palo Pinto County, population 19. He is the only doctor listed there. The 1904 edition has him still in Graford, but the population has grown to 24, one of that number being another doctor, J. M. Patterson.
But the Polk’s directory doesn’t tell the whole story, and maybe not even the correct story. I’m guessing that the 1902 mention at Graford is probably correct, but by the middle of 1903, IMH was listing his address on birth and death records as Christian, not Graford, which would make the 1904 listing another holdover. Polk’s does list one F. R. Bowles practicing in Christian in 1902 (population 50) and 1904 (population 90), but no IMH. The Standard Medical Directory of North America for 1903-04 lists both IMH and Bowles at Christian. It also adds that IMH was “licensed by examination without college diploma” and began his career in 1899.
And, since the good doctor was listing his address as Christian up to November 21, 1904, it’s safe to assume that that is where he and Hester Jane Ervin made their first home together after their January 12, 1904 marriage. (Today, the only remnant of that town is a road sign, “Old Christian Rd,” about five miles north of Graford.)
There are no documents to testify where the Howards were from December 1904 to May 1905, but we can hazard a few guesses.
During that time, the number of medical schools in Texas was expanding and Dr. Howard picked up his diploma from Gate City Medical College, over in Texarkana, on May 1, 1905. While “the founders of these schools had the best intentions to offer bona-fide instruction in medical science, [. . .] they had too few resources. Most of them ceased operations or were absorbed by other schools within a short time.” Gate City was closed in 1911 when it was caught selling diplomas, but I think it’s safe to assume that IMH spent a little time in Texarkana before being awarded his. 
Also during that time, the newlywed Howards approached IMH’s older brother, David Terrell Howard, about adopting his youngest son. Wallace Howard told L. Sprague de Camp that Dr. and Mrs. Howard, “they come to mama and papa and wanted to take me and raise me as their, their foster son.”  David Howard was farming in Limestone County at the time, some 125 miles southeast of Christian, and had quite a large family (six children in 1904, and 12 before he was finished having children in 1919). In 1977, Wallace Howard wondered if he “wouldn’t have been better off” going with the doctor, but nothing came of the plan and before the summer of 1905, Hester would have known that she was pregnant.
Another possibility is Dark Valley, a few miles southwest of Graford. In July 1977, L. Sprague de Camp interviewed Florence Green, who was close to 100-years-old at the time. In his notes, de Camp writes that “Hester and I. M. Howard came from Christian miles away to Dark Valley as a young married. They lived for several months with Mrs. Green who had a house a few feet away from the creek.” According to Green, the Howards stayed with her until their own place was built, “a little ways down the creek from the Green’s” and when it was time for Hester to give birth, “She went to Peaster, a much bigger town in those days, 1906, and some buggy ride away—a day’s journey—to have the child.” After Robert’s birth, the family returned to Dark Valley for a while, but “[t]hey moved away while Robert was a babe in arms—meaning anywhere from 1-2 years of age.” 
There are some problems with Green’s account. There is no record of the Howards buying any land in the vicinity of Dark Valley Creek; why build a home on property they did not own? Mrs. Green also, apparently, didn’t think it was relevant that it was Dr. Howard who recorded the birth of her daughter in 1907 (where he listed Graford on the Record of Birth); at least, it doesn’t show up in de Camp’s notes. Also, in Dark Valley Destiny, de Camp says, “During her pregnancy, Hessie was all smiles and laughter, forever joking with her neighbors, but she never left her husband’s side. She traveled with Dr. Howard wherever he went” (pg. 32), information that must have come from Green, but how would she have known this when, shortly after receiving his diploma, Isaac Howard registered his credentials over in Parker County on May 12, 1905, and his name begins appearing on birth and death records that same month? Hester would only have been about one month pregnant at the time. And Peaster wasn’t the first place they went to in Parker County.
On May 23, 1905, Dr. I. M. Howard filed a “Report of Death” for a two-day-old child. The doctor’s address is listed as “Whitt.” The 1904 Polk’s directory lists three doctors in Whitt and sets the population at 430, same as the 1906 edition; none of the listed doctors is IMH.
Shortly after his arrival in Whitt, Dr. Howard appears to have partnered with one of those other doctors, J. D. Pickens, as their names appear together frequently on birth and death records in June and July. The last birth record filed by Pickens/Howard is dated July 19; all of these records list IMH’s address as Whitt. After that July 19 filing, the record goes quiet until August 16, 1905, when Dr. Howard was awarded a “Certificate of Registration” from the Texas Board of Pharmacy indicating that he had “given satisfactory evidence that he is a Qualified Pharmacist.” After that, he moved to Peaster.
From late September to just after Christmas 1905, IMH was listing his address on birth and death records as Peaster. Like Whitt, Peaster already had a doctor or two. In fact, besides J. A. Williams, the doctor who recorded Robert E. Howard’s birth, there was also a Dr. J. M. Blackwell, with whom Dr. Howard planned to share office space, as reported in “Peaster Items,” from the Weatherford Weekly Herald for October 19, 1905:
All three doctors appear in the 1906 edition of Polk’s, which has the population of Peaster pegged at 240. (A July 8, 1921 article in the Cross Plains Review announced Blackwell’s arrival in the area and says that he “comes well recommended for his work. He is an old time friend of Dr. I. M. Howard of this place, and a former partner with him in the practice of medicine.”) All of which begs the question: Why was it Williams and not IMH’s partner, Blackwell, who recorded Robert E. Howard’s birth? If you’ve read this far, you probably already know the story. The Howards celebrated REH’s birthday on January 22, 1906, but, probably due to a delay in filing, Williams reported the birth as January 24. He filed the document on February 1st.
The last known sighting of the Howards in Peaster is a notice from the February 19 column, “Peaster Pencilings,” which appeared in the February 22, 1906 edition of the Weatherford Weekly Herald: “Dr. Howard is boasting of the only boy baby of Peaster in 1906.” After that, the trail is cold until a May 31, 1906 “Report of Birth” places him back in Graford, which is probably only where he received mail, since he was no doubt living in Dark Valley at the time.
All of the above makes the following paragraph from Dark Valley Destiny a bit shaky:
Robert Ervin Howard was born on January 24, 1906, in Peaster, Texas, a village in Parker County, ten miles northwest of Weatherford and thirty-five miles due west of Fort Worth. The Howards at that time lived in Dark Valley, a community of some fifty souls in Palo Pinto County, near the Parker County border; but Dr. Howard had taken his wife to Peaster, a larger settlement in the adjacent county, as her confinement drew near. He wished, presumably, to insure adequate medical facilities for her lying-in, as well as the services of Dr. J. A. Williams, the physician who attended Mrs. Howard at the birth of her only child. [pg. 18]
Patrice Lounet pointed out the biggest problem with this a few years ago: “If Dr. Howard wanted to ‘ensure adequate medical facilities’ for his wife, Peaster would not have been his first choice, but more likely the much larger Weatherford. Or even halfway from there, Mineral Wells, where physicians would be numerous.”  But if not for medical attention, then why?
In a 1977 interview with L. Sprague de Camp, Wallace Howard explained it this way: “The Howards are a moving people.”  And I can’t do much better than that. IMH seems to have been constantly on the look for greener pastures, and he never shied away from a dramatic move. Being a doctor himself, and having a partnership with another doctor (even though his partnerships never lasted for long), makes the “adequate medical facilities” argument seem a bit thin. I’m more inclined to believe that IMH saw an opportunity there that just didn’t pan out.
I’m fairly confident that one of the reasons IMH came to the Palo Pinto-Parker region in the first place was the railroad: “The Weatherford, Mineral Wells and Northwestern completed twenty-five miles from Weatherford to Mineral Wells in 1891. That year the company owned two locomotives and ninety cars. In 1895 it earned $15,561 in passenger revenue and $38,070 in freight revenue. The line was bought by the Texas and Pacific Railway Company in 1902,” the same year that IMH arrived.  And once the mainline was complete, the competition for spurs off of that line began, with rumors and speculation being reported in area newspapers every week; there was even some wild talk of turning the road into “a great transcontinental line” . Of course, nothing quite so grand happened; however, “Construction of an extension of the line to the city of Oran was completed in 1907, and on to Graford the following January.” 
[Map courtesy of Abandoned Rails]
It may have been these rumors and speculation that encouraged IMH to begin purchasing land in Palo Pinto County. On October 11, 1905, while living in Peaster, Dr. Howard purchased part of lot 1, block 7 in the town of Oran for $50. This must have been a simple investment since, as we have seen, after leaving Peaster the Howards settled in Dark Valley. IMH listed his residence as Graford on birth and death notices from May 31, 1906 until at least May 5, 1907. But he may have been planning a move even before then.
On January 19, 1907, he purchased Lot 6 in Block 54 of the town of Oran for $45. Then, on May 25, 1907, he spent $200 for lots 7 and 8 in Block 7. A few weeks later, June 14, 1907, IMH and wife Hester sold “the North East one fourth (1/4) of Block Seven (7)” for $300. Sounds like a pretty good deal for the Howards. Not long after that, if not before, the family was living in Oran. From August to December 20, 1907, IMH lists his address as Oran. The week before Christmas, he re-filed his credentials in Palo Pinto County to correct a transcription error in his initials from “S. M.” to the correct “I. M.” Two weeks later, he was in Big Spring, way over in Howard County. The West Texas adventure had begun.
1: Handbook of Texas Online, D. Clayton Brown, “Medical Education,” accessed September 11, 2016, http://www.tshaonline.org/handbook/online/articles/sfm02.
2: De Camp, L. Sprague: “Notes on Interview with Wallace C. Howard in Mart, Texas, 7/22/77,” unpublished, housed at HRC.
3: De Camp, L. Sprague: “Notes from interview with Mrs. Green and visit to Dark Valley with Mr. John Dean McClure,” unpublished, housed at HRC.
4: Louinet, Patrice: “The Long Road to Dark Valley—Introduction,” accessed September 11, 2016, http://www.rehtwogunraconteur.com/the-long-road-to-dark-valley-introduction/
5: De Camp, L. Sprague: “Notes on Interview with Wallace C. Howard in Mart, Texas, 7/22/77,” unpublished, housed at HRC.
6: Handbook of Texas Online, Chris Cravens, “Weatherford, Mineral Wells and Northwestern Railway,” accessed September 11, 2016, http://www.tshaonline.org/handbook/online/articles/eqw08.
7: “Doing Our Best,” The Daily Herald. (Weatherford, Tex.), Vol. 7, No. 218, Ed. 1 Monday, September 24, 1906.
8: The Weatherford, Mineral Wells, Northwestern Railroad Depot, photograph, 1990?; (texashistory.unt.edu/ark:/67531/metapth29853/: accessed September 11, 2016), University of North Texas Libraries, The Portal to Texas History, texashistory.unt.edu; crediting Boyce Ditto Pub