Dermacentor andersoni, commonly known as the Rocky Mountain wood tick, is a species of tick

Tick

Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...

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It can cause tick paralysis

Tick paralysis

Tick paralysis is the only tick-borne disease that is not caused by an infectious organism. The illness is caused by a neurotoxin produced in the tick's salivary gland. After prolonged attachment, the engorged tick transmits the toxin to its host...

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Diagnostic features:
Larva only has 3 pairs of legs.
Nymph has 4 pairs.
Single pair of spiracular openings (stigmata) close to the coxae (leg bases or segments) of the 4th pair of legs (except in larvae)
Terminal capitulum (mouthparts) visible from above in all stages except
the egg, of course.
A large sclerite called the Scutum present dorsally behind the capitulum.
The scutum almost entirely covers the back of the male, but only partly covers the back of the female.
Eyes, if present, are on the scutum.
Sexual dimorphism in size and colour is frequent.
The female is often larger.
Posterior margin of opisthosoma usually sub-divided into sclerites callel
festoons.
Pedipalps rigid along the chelicerae, not leg-like.
Single pair of spiracular openings (stigmata)