Map at right generated by LonelyPlanet.com free personal travel website service.
Unfortunately, there is no excellent trekking map for Colca Canyon.
If you are day hiking, or doing the regular 2-day hike, you probably will not need one.
For the 5-day trek to Andagua, we would love to have had a good map. We didn’t.
IGN 1:100,000 Chivay (sheet 32-s), Huambo (sheet 32-r) & Orcopampa (sheet 31-r) cover the 5-day trek, but roads & tracks are not up-to-date.
We did not buy the 3 maps, instead relying only on the guidebook map in Lonely Planet Trekking in the Central Andes.
If you must have the topographical maps, get them at South American Explorers Club Cuzco or Lima (Miraflores) when you get to Peru.
We were frequently confirming the best route with locals & with guides from other groups. Conversational Spanish is a big advantage.
Luckily, the farmers & shopkeeps were friendly & welcoming.
You can amass a collection of free not-to-scale hand drawn maps from iPeru (the official tourist information centre on the plaza in Arequipa) & various trekking agencies. We had 3 maps (one scrawled on the back of a placemat) as well as the LP trekking guide when we descended.
You may want to consult or even print out one of the online maps (they open in another window) while planning your hike:
