What recourse do beneficiaries have if a Personal Rep refuses to communicate with them?

You can petition the court either to remove the PR or to order the PR to provide an accounting.

In Colorado, a personal representative is usually supervised by the court but may also be allowed to conduct the administration of a will without supervision. However in every case, the personal representative has fiduciary duties to the beneficiaries of an estate. Under Colorado law, the personal representative must value, consolidate, and/or liquidate the estate’s assets. This takes time. However, the personal representative must keep accurate records of the estate’s transactions, and must make distributions to creditors, devisees, and/or heirs. If the personal representative fails in his or her fiduciary duties any interested party may petition the Court to appoint a new personal representative.