Loop 108 begins at an intersection with SH 87 near Fort Travis Seashore Park on the Gulf of Mexico in Galveston County, heading northwest on two-lane undivided 7th Street.

Here, Loop 108 turns northeast onto Broadway Avenue while Spur 108 continues northwest on 7th Street.

The highway heads between residential areas and wetlands before leaving Port Bolivar.

[1][2][3] Loop 108 runs through more coastal marshes and turns southeast onto Kingston Beach Road, ending at another intersection with SH 87.

[7] The entire route is in Port Bolivar, Galveston County.