Klingsheim v. Cordell, 2016 CO 18

The Cordells owned two adjacent La Plata County parcels and failed to pay taxes for multiple years; tax liens were purchased and assigned to Bradley Klingsheim, who requested treasurer's deeds.
La Plata County Treasurer published statutorily required notices and mailed certified-mail notices to addresses on the county tax rolls (705 N. Vine, Farmington, NM) for each tract.
Certified-mail return receipts were signed by "Cleo Cordell" at 708 (or adjacent) North Vine; the Treasurer received the signed receipts and took no further action.
The Treasurer later issued deeds to Klingsheim; the Cordells discovered the notices at the mother’s home but missed the statutory redemption period and sued to void the deeds.
The trial court found the Treasurer failed to perform a diligent inquiry and voided the deeds; the court of appeals affirmed; the Colorado Supreme Court granted certiorari.

Issue	Plaintiff's Argument (Klingsheim)	Defendant's Argument (Cordells)	Held
Scope of treasurer's post-mailing duty of diligent inquiry under § 39-11-128(1)	Treasurer satisfied statutory duties by mailing to address on tax rolls and need not investigate further after signed receipts	Receipt signed by third party at nearby address should have triggered further search of county records and re-mailing	Treasurer has initial duty to inquire for addresses before sending notice; a further duty to inquire arises only when facts known show taxpayer could not have received notice; here no further duty arose
Whether the notices satisfied due process	Certified mail to longstanding address, signed by relative/agent, was reasonably calculated to inform the Cordells	Actual receipt was not shown; signature by someone else and at adjacent address undermines notice sufficiency	Notice met due process: certified mailing to address on tax rolls, accepted by a family member at an adjacent address, was reasonably calculated to notify

Bald Eagle Mining & Ref. Co. v. Brunton, 487 P.2d 59 (Colo. 1968) (treasurer must make diligent inquiry to learn record owner's address before mailing)
Siler v. Investment Securities Co., 244 P.2d 877 (Colo. 1952) (returned mail to an outdated address supports finding of insufficient inquiry)
Schmidt v. Langel, 874 P.2d 447 (Colo. App. 1993) (returned/forwarded notices require treasurer to re-examine county records for alternative addresses)
Parkison v. Burley, 667 P.2d 780 (Colo. App. 1983) (undeliverable returns obligate reexamination of assessor's records)
Columbus Invs. v. Lewis, 48 P.3d 1222 (Colo. 2002) (actual receipt not required; reasonable diligence suffices)
Jones v. Flowers, 547 U.S. 220 (2006) (due process requires notice reasonably calculated under the circumstances)
Mullane v. Central Hanover Bank & Trust Co., 339 U.S. 306 (1950) (constitutional standard for notice: reasonably calculated to apprise interested parties)