Austin and volcanoes (Spring, Burleson, Lockhart: school, airport, deposits)

[oldtoiletsmkgdflrpots]

Is this wiki article pretty accurate?

Pilot Knob (Austin, Texas) - Wikipedia, the free encyclopedia

[capcat]

I believe so...I know nothing of the details, but I knew that it's there.

[Creedmoor_Mom]

Guidebook to the Geology of Travis County
From UT Library....

[Willsson]

From the Handbook of Texas Online...

...eight miles southeast of Austin in southern Travis County. It was named for a nearby geological feature believed to be the remains of a cretaceous volcano.

Creedmoor_Mom's link is has much more information.

[atxcio]

Originally Posted by Creedmoor_Mom

Guidebook to the Geology of Travis County
From UT Library....

Can anyone make sense of those directions at the bottom of this link? It was obviously made a long time ago, before the 1999 opening of ABIA as our airport and long before 130. But still, I can't see how those road directions work. It does seem like the site they describe maybe located right at... well, you can guess where.

[Creedmoor_Mom]

Originally Posted by atxcio

Can anyone make sense of those directions at the bottom of this link? It was obviously made a long time ago, before the 1999 opening of ABIA as our airport and long before 130. But still, I can't see how those road directions work. It does seem like the site they describe maybe located right at... well, you can guess where.

ROFL!! I just looked the front cover & the book was published in 1977!!

[CptnRn]

Originally Posted by atxcio

Can anyone make sense of those directions at the bottom of this link? It was obviously made a long time ago, before the 1999 opening of ABIA as our airport and long before 130. But still, I can't see how those road directions work. It does seem like the site they describe maybe located right at... well, you can guess where.

They are not clear to me either. I could not find an Elroy Road or Bluff Springs Road in the area SW of the airport when looking at google maps. If you take Burleson Road further East it is called Elroy Road, so the name probably changed recently. Google Maps did pinpoint the intersection of FM 812 and 183 as Pilot Knob when I typed that into the search window. The description below mentions a Cottonmouth Creek and there is a Cottonmouth School Road near the intersection. There is a section of Bluff Springs Road over near IH-35 that turns into Old Lockhart Highway. So these instructions below don't make any sense with current road names.

Pilot Knob can be reached by driving out Highway 183 past Bergstrom Air Force Base (soon to be Austin's-Bergstrom International Airport). As you cross Onion Creek the Knob is visible ahead to your right. A circuit of the volcanic complex can be made by turning off Highway 183 onto Elroy Road (to the right) and following Elroy Road to the intersection with Bluff Springs Road, where a left turn leads back to Highway 183. Elroy Road closely follows the northern topographic rim of the volcano formed by the escarpment of the Cretaceous beach rock mentioned earlier. The lowland drained by Cottonmouth Creek and underlain by soft, easily eroded volcanic ash and other pyroclastic deposits, and the central core area formed by the resistant trap rock are easily visible to the south of Elroy Road. About 2/3 of a mile east of the intersection of Bluff Springs Road with Elroy Road, the trap rock of south Pilot Knob crops out along the road. This rock is very similar to that which forms the center of the volcano, and may represent the eroded remnant of a lava flow erupted along the flanks of the volcano or having flowed down the south side from the apex.

[atxcio]

Originally Posted by CptnRn

They are not clear to me either. I could not find an Elroy Road or Bluff Springs Road in the area SW of the airport when looking at google maps. If you take Burleson Road further East it is called Elroy Road, so the name probably changed recently. Google Maps did pinpoint the intersection of FM 812 and 183 as Pilot Knob when I typed that into the search window. The description below mentions a Cottonmouth Creek and there is a Cottonmouth School Road near the intersection. There is a section of Bluff Springs Road over near IH-35 that turns into Old Lockhart Highway. So these instructions below don't make any sense with current road names.

Ah, ok... I just thought of something thanks to your message. I was assuming "After crossing Onion Creek exit to the right" meant the site was north of Onion Creek, and east of 183. How silly of me. Obviously, from UT they would be heading south... so it's south of Onion creek and west of 183. Then not far from the site you found of the School, there is a "Cotton Bluff Springs Rd" that makes a loop back to 183 as described in the directions. So I will assume that's the "Bluff Springs" road they are talking about.

That would make the "Elroy Rd" they are referring to actually Dee Gabriel Collins Rd (which is the road the Wikipedia article mentions). And if you look at streetview from there, I think can you see the view they are describing: cottonmouth school road austin, tx - Google Maps

Anyway, I'll bet Dee Gabriel Collins was named more recently than the original UT article. I don't think it was Burleson Rd, since that's north of Onion Creek. Perhaps back then Dee Gabriel Collins Rd was named Elroy Rd.. since it would have gone to Elroy, TX (along the route of FM812.. which it could have been part of at one time when all that was way out in the country). Wasn't it traditionally the case that roads would often be named for where they went, originally? Like the "Bastrop Highway", "Lockhart Highway", "Manchaca Rd", etc?

[Pmpiper]

Do a search of elroy road, texas. in Google

[TexasHorseLady]

Bluff Springs Road is also the Old Lockhart Highway.

Burleson Road becomes Elroy Road east of 130.