File talk:Naun 1428.jpg
This does not appear to be Hill 1428.
It appears to be a hill inside Laos at 17°47′50″N 101°2′17″E / 17.7972°N 101.03806°E looking north from Phu Soi Dao National Park instead of south.
I matched it to the photo using Google Earth viewing from Phu Soi Dao National Park at 17°44′30″N 100°59′19″E / 17.7417°N 100.98861°E looking north-north-east.
Hill 1428 is actually south of Phu Soi Dao National Park I believe at 17°37′16″N 100°58′37″E / 17.62111°N 100.97694°E, and Ban Rom Klao at 17°35′41″N 100°54′32″E / 17.59472°N 100.90889°E.
See map in [ERG-10] http://www.icwa.org/wp-content/uploads/2015/10/ERG-10.pdf (I used Bing maps to correlate the place names with Google Earth which doesn't list those places.)
[ERG-10] Erik Guyot to Peter Martin, "Sibling Rivalry: The Thai-Laos Border Conflict," Institute of Current World Affairs letter, 1988 — Preceding unsigned comment added by Crispience (talk • contribs) 09:12, 26 March 2021 (UTC)