I claim the ornamental design for a saddle rope holder, as shown and described.
FIG. 1 is a perspective view of a saddle rope holder, showing my new design shown in a position of use;
FIG. 2 is a perspective view shown in a flat configuration;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left-side elevational view thereof;
FIG. 6 is a right-side elevational view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines showing a saddle and rope in FIG. 1 depict environmental matter and form no part of the claimed design. The boundary lines next to the star represent the boundary of the claim.