“Bastropian” is the name of an inhabitant of Bastrop, Texas. The name “Bastropian” has been cited in print since at least 1892.
 
“Bastropite”—less frequently used—has been cited in print since at least 1867.
 
       
Wikipedia: Bastrop, Texas
Bastrop is a city and the county seat of Bastrop County, Texas, United States. Located about thirty miles southeast of Austin, it is part of the Greater Austin metropolitan area. The population was 5,340 at the 2000 census. By 2007, the city had an estimated population of 7,823, twice the population of the early 1970s.
 
30 August 1867, San Antonio (TX) Express, pg. 2, col. 3:
Mr. Borden owns a “cedar tract” near Bastrop, Texas. The machinery is already purchased for a sawmill and factory, the latter to compress two and a half pounds of bee into cakes of two ounces. So the Bastropites may look for “big things” in as short a time as it will take to become constructed.
 
2 November 1892, Dallas (TX) Morning News, pg. 4:
Hogg at Bastrop.
BASTROP, Tex., Oct. 31.—The political pot no longer simmers, but is boiling, and men, women and children alike stand committed and interested in the vital issues to be settled at the polls Tuesday week. Governor Hogg spoke to a packed opera house in the city Tuesday, and old Bastropians, who indorse the Clark faction of the democratic party, smiled when Senator Fowler introduced him as “the regular democratic nominee for whom all good democrats should vote.”
   
28 September 1894, Galveston (TX) Daily News, pg. 4, col. 6: 
SAYERS-HUTCHISON.
Bastrop, Tex., Sept. 26.—Quite a large delegation of Bastropians went out to Hill’s prairie (Gospel shed) yesterday to the barbecue and joint debate between Hon. J. D. Sayers and his populist opponent, Maj. W. O. Hutchison.
 
OCLC WorldCat record
The Bastropian, 19 : a visitor’s guide to shopping & recreation in historic Bastrop.
Publisher: np.
Edition/Format:  Book : English
 
Google Books
Butterbean: When glory’s just a whisper:
The authorized biography of Bob Love
By Rick Davis
Chicago, IL: Butterbean Productions
1994
Pg. 15:
Some Bastropians, weathered by time and clouded by age, still live to tell their versions of the events of July 9, 1934.
(The basketball player Bob “Butterbean” Love was born in Bastrop, Louisiana—ed.)
     
Austin (TX) American-Statesman
Clouds, higher humidity on tap today
By Claudia Grisales | Wednesday, October 5, 2011, 08:08 AM
(...)
COMMENTS
By GoFaster58
October 5, 2011 10:19 AM
Bastropians (Bastropites? Bastropers? Anyone know the answer here?) can’t seem to get a break.
 
Austin (TX) Chronicle
You: Part of Hammer History
Wayne Alan Brenner
1:39pm, Wed. Nov. 2, 2011
(...)
Now some hundreds of your fellow Austinites (and Bastropians and Elginistas and Lockhartons and so on) are gathering in the wilds of East Austin, all decked out in their best denim duds to knock this thing into the history books.