ZIP Code 78663

78663 is one of Texas's ZIP codes, delivering to addresses in Round Mountain, Blanco County.

City: Round Mountain
County: Blanco County
State: Texas
Prefix: 786xx

Where this code sits

78663 is part of the 786xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Round Mountain.

Round Mountain Texas ZIP codes →

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 78663 delivers to without sharing its boundary.

830 Area code 830

ZIP codes nearest 78663

The ZIP codes whose reference points sit closest to 78663.
ZIP code	Distance	Delivers to
ZIP code 78657	7.9 mi	Horseshoe Bay, TX
ZIP code 78636	11 mi	Johnson City, TX
ZIP code 78654	13 mi	Marble Falls, TX
ZIP code 78675	14 mi	Willow City, TX
ZIP code 78639	15 mi	Kingsland, TX
ZIP code 78635	16 mi	Hye, TX
ZIP code 78671	19 mi	Stonewall, TX
ZIP code 78643	22 mi	Llano, TX

Straight-line distance between place reference points, not driving distance. Where a place has no Census Gazetteer point, its postal centroid is used instead.

Each point is the reference point for 78663, plotted from its record coordinates.

Reference points and footprint
Not an official NANPA boundary
Not a USPS delivery area

Scope ZIP code 78663. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. A ZIP code is a set of delivery routes, not an area; the point shown is a record coordinate, not a centre.