Hi,
It looks like there were about 14 narrow gauge common carriers in Texas (According to Hilton - I reccomend the book highly - American Narrow Gauge RRs).
Briefly:
1) Austin & NW - Austin to Wilkie to Burnet and Wilkie to Marble Faills. built 1881-2, SG 1891 - was to connect to the Texas and St. Louis' grade from near Waco to Eagle Pass (narrow Gauge Trunk).
2) Brownsville & Gulf - "Rio Grande RR station in Brownsville to ferry landing" - 36" gauge.
3) Dallas, Cleburne & Rio Grande Ry - 1879 - 53 miles - 1 passenger & 1 freight run. No regular operation. bought in 1882 and standard gauged.
4) East Line and Red River - 155 miles 1881 - Jefferson to McKinney - converted 1892 - now part of MKT.
5) Galveston, Brazos & Colorado - 1877 - blown away in hurricane of 1900.
6) Galveston, Sabine & St. Louis - logging RR incorporated in 1877 - converted 1887 - absorbed by AT&SF.
7) Houston East & West Texas - 1878 - 232 miles - converted 1895 - became part of St Louis Southwestern.
Kansas and Gulf Short Line - Tyler to Lufkin - 90 miles - 1880 - converted 1895 - absorbed into St Louis Southwestern 1899.
9) Kildare & Lindon - 13 miles 1889-1900 - logging.
10) Rio Grande & Eagle Pass - SG line allied with 36” gauge Texas-Mexican. SG March, 1883 - dual August 1884 - SG 1895.
11) Rio Grande RR - 42” gauge - 22 miles - built 1873 - SG 1925 - part of MoPac.
12) Texas-Mexican - 161 miles - 1877-1881 - SG 1902 - run as extension of NdeM in US.
13) Texas Western - chartered 1870 for a gauge of anywhere between 24” and 5' 6” - 1875 36” gauge chosen - Pattison to Houston - 1876 - abandoned 1899 - competed with MKT SG line to Sealy 3 odd miles to the north of the TW.
14) Warren & Corsica - 18 miles - 1899-1907 logging.
I hope this wets your appitite.
Doug vV