This story is similar to several Roy stories credited to the team Al McKimson, Randy Steffen, Alvarado and Andrew Bensen by Robert W Phillips.
See Roy Rogers #24 Silver Spider, #25 Trades Lead, #26 Jerkline Feud, #27 Mustang Mountain, and #28 Apache Blood.
The art may vary a bit since several of them worked on the same story (also by R W Phillips)
Al McKimson was a pen name for several artists. First the brothers Chuck and Tom McKimson. Others were Pete Alvarado, John Ushler, Randy Steffen, Andrew Bensen, Hi Mankin, Mike Arens, Alex Toth.
Art identification by Steinar Ådland December 2010.
Artwork similar to Trigger in RR# 25, credited to Harry Parks.
Art identification by Steinar Ådland December 2010