The Naruskajoki flows through northern Salla for about fifty kilometres from Lake Naruskajärvi to the Tenniöjoki junction at the southern edge of Naruska village. From there the Tenniöjoki and Naruskajoki continue as the Tenniöjoki towards Savukoski, where they join the Kemijoki. The Kemijoki continues to Pelkosenniemi and on through Kemijärvi to Rovaniemi. The Kemijoki ends at the Bothnian Bay in Kemi.
Before the harnessing of the Kemijoki, salmon once ran up the Naruskajoki from the Bothnian Bay — but those days are gone. Nevertheless, the Naruskajoki sustains good natural populations of brown trout, grayling and whitefish. Even in the pool sections, you might land a "jänkäkoira" — the local name for pike — though perch are also present, though less numerous than the salmonids.
The return of salmon is a dream nurtured especially here on the headwaters. Kari Kilpimaa, head of the Savukoski-based Ylikemi Fishing Area, has for years actively campaigned for fish passes to be built at the Kemijoki hydropower plants, which would allow salmon to run all the way to Naruska — once a spawning ground and fishing river for Bothnian Bay salmon. Time will tell who wins.
The Naruskajoki was cleared as a floating channel along its entire length for decades but was restored in the early 1990s. The intention was that a clear central channel for paddlers would remain, but in practice the restored river, with its boulder-filled rapids, is difficult and even dangerous for fibreglass craft. Paddling the Naruskajoki requires good rapids-reading skills. An easy stretch of about twenty kilometres of pool water is found in the middle section of the river, from the Suoltijoki–Naruskajoki confluence downstream. This pool stretch ends at the Naruskajoki's ten-kilometre rapids run, which contains challenging white water. Siekakönkäs, for example, has been stoned for a slalom-style course, so running it — especially during high water — requires solid paddling skills. It is advisable to check water levels before setting out to paddle the Naruskajoki, as the water both rises and falls rapidly with summer weather.
As a fishing river, the Naruskajoki offers varied and highly accessible water along its entire length. The banks are mostly easy to walk, though wooded and bushy. They are generally firm underfoot. The Naruskajoki is suitable for bank fishing and for wading with a fly rod in the rapids sections. Craft can be used in the pool sections. When in flood, currents are powerful, so it is worth waiting for the spring flood to drop to summer levels. A heavy mid-summer rain can also raise the Naruskajoki's water level quickly for a day or two after the rain, though dry weather brings it back down just as fast. These water-level fluctuations are characteristic of this "vertical river". Fish feeding activity tends to be sluggish when the water is highest, as locals say.
There are good fireplace rest stops along the Naruskajoki. The southernmost is by the Siekakönkäs bridge in Naruska village. The Naruska Village Association's kota is at Haltinmutka, where there is also a swimming beach marked on the main road's left side heading north. The Haltti kota is on the west bank of the river, a kilometre upstream (northward) from the village association's kota. By the Suoltijoki bridge there is a nut-bolt kota with a fireplace. Going upstream from there along the Naruskajoki, there is a kota on the west bank at Pystökoski. Near the south end of Lake Naruskajärvi, by the Naruskajoki dam, there is also a nut-bolt kota with a fireplace.
The Naruskajoki is part of the Ylikemi Fishing Area's waters. The permit area includes the tributaries draining from the west into the Naruskajoki, but the rivers draining from the east are not included.
Fly fishers wading the river should bear in mind that the boulders returned to the river during restoration are split rocks that can tip like see-saws if you step on them, so caution and care are essential when wading.
The Naruskajoki is also well suited to winter fishing. The pool sections freeze in autumn at almost the same rate as lake waters. In early winter especially, trout are actively feeding for the ice angler. In mid-winter and particularly in spring, grayling and whitefish join the trout as catch for the ice angler. The best time for ice fishing for whitefish falls in April, when several pools of the Naruskajoki have age-old whitefish feeding spots, especially in the evenings.