B.  Timing of the Notice

Reference
The return receipt cards and notices must be filed with the court. 

C.R.S § 19-1-126(1)(c)
If the child has been identified as an Indian child before the petition is filed, the return receipt cards should be attached to the petition. 

C.R.S  § 19-1-126(1)(c)
If notice has not been perfected by the time the petition is filed, or if the return receipt cards have not been received, then the petitioning party should let the court know of those circumstances and file the return receipt cards within ten days after the petition is filed. 

C.R.S § 19-3-602(1)(b)
If a motion to terminate has been filed, the return receipt cards should be attached to that motion or filed within ten days after the motion is filed.

25 U.S.C. § 1912(a)

People in Interest of S.R.M., 153 P.3d 438 (Colo. App. 2006)
The ICWA requires the notice to be received at least ten days before the hearing in involuntary proceedings in which a party seeks to:
  • Place a child in foster care; or
  • Terminate parental rights.
C.R.S § 19-1-126(c)
Colorado law also requires notice to be served before the petition is filed if the child is known to be an Indian child.

People in Interest of T.R.W., ___ P.3d ___ (Colo. App. Nos. 08CA2335 & 082336, Apr. 2, 2009)
Notice must be given for each child; neither the social services department nor the court may rely on notice given for a sibling as dispositive as to another child. 
Reference
This is because the tribe is free to change its enrollment criteria at any time.

B.H. v. People in Interest of X.H., 138 P.3d 299 (Colo. 2006)
Sufficiently reliable information of virtually any criteria on which membership might be based must be considered adequate to trigger the ICWA’s notice provisions.

B.H. v. People in Interest of X.H., 138 P.3d 299 (Colo. 2006)
The threshold criteria for notice is not intended to be high.
B.H. v. People in Interest of X.H., 138 P.3d 299 (Colo. 2006)
Membership criteria include, but are not limited to:
  • Enrollment;
  • Blood quantum;
  • Lineage;
  • Residence on a reservation. 
B.H. v. People in Interest of X.H., 138 P.3d 299 (Colo. 2006)
Otherwise sufficiently reliable information cannot be overcome by the statements, actions, or waiver of a parent or disregarded as untimely.

25 U.S.C. § 1912(a)
 25 C.F.R. § 23.12
Notice shall be given by registered mail, return receipt requested. Service of notice must be on a tribal agent designated by the tribe. Current names and addresses of the designated tribal agents are found at 71 Fed. Reg. 43788.