Discovery across state lines runs through the UIDDA.

Inbound — a foreign subpoena lands in Colorado

"This article may be cited as the Uniform Interstate Depositions and Discovery Act"

C.R.S. § 13-90.5-101

"a party must submit a foreign subpoena to the district court for the county in which discovery is sought to be conducted in this state. A request for the issuance of a subpoena under this section does not constitute an appearance in the courts of this state"

C.R.S. § 13-90.5-103(1)

The mechanics in one line: take the out-of-state subpoena to the district court for the county where the discovery will happen, and the clerk issues a Colorado subpoena on its terms — no pro hac vice, no appearance, by the statute's own words.

Outbound — a Colorado case needs discovery elsewhere

The receiving state's own UIDDA (or its non-uniform equivalent) governs. This platform states only Colorado's loaded law — the destination state's procedure must be read at the destination. Sibling TrialVector states with their interstate lanes loaded: North Carolina and Arizona.

The statutory subpoena layer beneath it

Enforcement of a subpoena duces tecum is statutory (C.R.S. § 13-90-112), and service of subpoenas rides § 13-90-115 — both loaded, read whole on their own pages. The subpoena RULE (C.R.C.P. 45) stays at the vendor boundary, named on the discovery-boundary page.