Commercial Fixed Wing
Situational Awareness
Conflict Airborne Conflict
Flight Crew FLC complied w / Automation / Advisory; Flight Crew Took Evasive Action
Airspace Structure; Human Factors
On the RNAV RNP Z RWY 05 Approach in visual conditions; SEA Center advised two targets maneuvering around the DSD VOR. One aircraft was no factor and clear; the other aircraft he said would present an issue. Neither [aircraft] seemed to be talking on the frequency. As we kept descending on the approach; near WONEK which is near the DSD VOR; we got the TCAS RA commanding a climb to avoid traffic off the left; maneuvering. After clear of conflict; we reestablished on the glide path outside the FAF; and landed in visual conditions.RDM is getting more chaotic with the increased flight training and air carrier operations. A note on the airport information chart would be appreciated about flight training. Also; maybe an outreach to the flight school advising them that if RDM is landing 05 and 29; be vigilant and be required to monitor SEA Center (128.15) if maneuvering near the DSD VOR.
Air carrier Captain reported receiving an RA on arrival into RDM from light plane traffic in the vicinity of the DSD VOR.