US passport. I'm planning on entering by land with the 30 day visa exemption and getting a 30 day extension on that at the local immigration office in Bangkok.
Can someone drop a link to website or provide the address of the office on Bangkok where one would gets this done?
TLDR : Answer Summary
You can extend your 30-day visa exemption at the Chaeng Wattana Immigration Office in Bangkok. Here are some resources to help you: the office is located at the Government Complex, and you can view it on Google Maps [here](https://www.google.co.th/maps/place/Immigration:+Government+Complex/@13.8975417,100.5222029,13z/data=!4m8!1m2!2m1!1schaengwattana!3m4!1s0x30e2832fce4f7053:0xe2cc4a5263fad687!8m2!3d13.880173!4d100.5646232). For detailed access information, check their official site [here](https://division1.immigration.go.th/content/contact), and you can find a list of all branches [here](https://www.immigration.go.th/branch_center).