The ornamental design for a mountablesubstrate having a cup holder and a smokingapparatuskeeper, as shown and described.
FIG. 1 is a perspective view of a mountable substrate having a cup holder and a smoking apparatus keeper, embodying my new design;
FIG. 2 is a top plan view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a first side elevation view thereof;
FIG. 5 is a second side elevation view thereof;
FIG. 6 is a third side elevation view thereof; and,
FIG. 7 is a fourth side elevation view thereof.
The broken lines shown are included for the purpose of illustrating portions of the mountable substrate having a cup holder and a smoking apparatus keeper that form no part of the claim.