The 39-year-old off-road runner received a deep wound near her thigh and had to be airlifted out of the grassy alpine area Nittedal, a popular wintertime ski resort.
“She probably has a broken femur,” Romerike police chief Arild Ruud told news agency NTB.
The attack occurred on Monday night just after 7pm in an area teeming with young and old joggers who witnessed the attack.
Norwegian conservation authorities are looking for the bull, although photographs showing the injured runner lying prone in wet alpine grass also show a female elk standing in the background just 15 metres away.
Conservation authorities say male elks are known to grow increasingly agitated during their spring and autumn rut, or mating seasons. Canadian wildlife web sites are rich with warnings that the male moose, as the animal is called in North America, is the forest’s most dangerous animal during these times.
The male will go out of his way to charge a person and cross great distances in just seconds to launch an assault with what can be a 1.5-metre wide set of spiky antlers, or horns.
The European elk tends to stand a full 30 centimetres shorter than its North American counterpart. Males typically weigh in at about 550 kilograms.