This is a direct appeal from the Oregon Tax Court’s denial of several motions to intervene in a mandamus proceeding. For the reasons that follow, we affirm the Tax Court’s order.

Relator is a taxpayer who filed a petition for an alternative writ of mandamus in the Tax Court, pursuant to ORS 311.215,1 alleging that Janice Druian, in her capacity as Director of Assessment and Taxation for Multnomah County (the director), failed to place several hospitals (the hospitals)2 on the tax rolls that were not entitled to property tax exemptions. The Tax Court issued an alternative writ of mandamus and scheduled a return date for a show cause hearing.

At the show cause hearing, relator presented information that, he argued, established that the hospitals should be added to the tax rolls. The director did not contest that information, but argued instead that her office lacked the resources to carry out the statutory requirements for adding a property to the tax rolls — such as valuing the hospitals’ property — until she was assured that the property was taxable.

A month after the show cause hearing, and while the matter was still under advisement in the Tax Court, the hospitals became aware of the mandamus proceeding. They moved to intervene, asserting that relator had not supplied the court with “credible information” to support his claim that the hospitals should be added to the tax rolls. The Tax Court denied the motions to intervene3 and issued a peremptory writ of mandamus, pursuant to ORS 311.207,4 ordering *319the director to issue notice to the hospitals, as provided by ORS 311.209,5 requiring the hospitals to show cause why they should retain their tax-exempt status. The Tax Court concluded that relator had produced “credible information” to support his claim that the hospitals were not entitled to property tax exemptions:

“The information ** * * is credible in the sense of being trustworthy because the information was furnished by the hospitals to a government agency. The information is also credible in the sense that it directly relates to the question of whether the property is used exclusively for charitable purposes.”

The hospitals moved for recall of the peremptory writ and reconsideration of its issuance on the ground that relator had failed to provide “credible information” to support the writ. In March 1996, the Tax Court denied those motions. The hospitals now appeal from the orders denying their motions to intervene.6

The hospitals argue that both ORS 34.130(4) and Tax Court Rule (TCR) 33 C govern the intervention of parties in a mandamus proceeding in the Tax Court and that both the statute and the rule authorize the Tax Court to allow them to intervene in this case. The hospitals also argue that, if the statute and the rule are interpreted to conflict, the statute takes precedence over the rule.

*320ORS 34.130(4) provides, in part:

“At any time subsequent to the return date of [an] alternative writ [of mandamus], the court in its discretion may allow an adverse party to intervene.”

It is undisputed that the hospitals qualify as “an adverse party’7 and that they sought to intervene after the return date of the alternative writ of mandamus.8 The word “may’ in the text of ORS 34.130(4) makes clear that the Tax Court had discretion to allow the hospitals’ motions to intervene. Therefore, if ORS 34.130(4) governs this case, then we review the Tax Court’s denial of the motions to intervene for an abuse of discretion.

Relator argues that TCR 33 C governs whether the hospitals may intervene in this mandamus proceeding. That rule provides:

“At any time before trial, any person who has an interest in the matter in litigation may, by leave of court, intervene. In exercising its discretion, the court shall consider whether the intervention will unduly delay or prejudice the adjudication of the rights of the original parties.”

Relator argues that the show cause hearing in this case constituted a “trial” for the purposes of that rule. From that premise, relator reasons that the hospitals failed to file a timely motion to intervene, because their motions were not filed “before trial.”

Relator’s argument is unpersuasive. We need not decide whether the show cause hearing in this mandamus proceeding constituted a “trial” under TCR 33 C because, even assuming that it did, ORS 34.130(4) still would govern this proceeding. The Tax Court is authorized only to promulgate rules that conform “as far as practical to the rules of equity practice and procedure.” ORS 305.425(3). Here, relator’s interpretation of TCR 33 C does not conform with ORS 34.130(4) because, under that interpretation, the Tax Court *321lacked authority to allow the hospitals to intervene due to the untimeliness of the hospitals’ motion to intervene. Under ORS 34.130(4), however, the motions to intervene were timely; therefore, the Tax Court had discretion to allow the hospitals to intervene. Relator has presented no explanation for why it would not be practicable in this instance for the rule — as it is interpreted by relator — to conform with ORS 305.425(3), nor are we aware of any. Relator’s interpretation of TCR 33 C is not well taken.9

We turn to the issue whether the Tax Court abused its discretion in denying the hospitals’ motions to intervene. The hospitals argue that the Tax Court abused its discretion, because the hospitals were the only parties that were prepared to give the Tax Court “credible information” upon which a proper determination could be made concerning whether the director was required to conduct a hearing to determine whether property should be added to the tax rolls. In other words, the hospitals argue that relator did not provide the Tax Court with credible information to support the issuance of a peremptory writ. We find that argument to be unpersuasive.

The hospitals apparently equate the requirement of ORS 311.215 — that a relator provide “credible information” to support the issuance of a peremptory writ — to a requirement that a relator provide the Tax Court with information that is more probative than contrary information that exists. We do not agree with that interpretation. The Tax Court found, as a matter of fact, that the information was credible (1) “in the sense of being trustworthy because the information was furnished by the hospitals to a government agency,” and (2) in the sense that it directly relates to the question whether the property is used exclusively for charitable purposes. We agree with that finding and conclude that relator’s information was credible within the meaning of ORS 311.215.

*322We note that the hospitals have the opportunity to challenge relator’s claims that they are not tax exempt, on the merits, at the administrative hearing required by the peremptory writ. At that time, the hospitals may persuade the director that they should not be placed on the tax rolls. The hospitals’ ultimate objection appears to center around the consequences of that administrative hearing. They assert that relator normally would not have standing to appeal to the Department of Revenue the director’s decision to leave the hospitals off the tax rolls. See ORS 305.275 (providing that only an aggrieved person whose property is affected by an act or omission of a county assessor may appeal to the Department of Revenue). Therefore, the hospitals do not think it fair that relator can avoid that asserted statutory bar to appeal by initiating this mandamus proceeding, which does allow for appeal by a taxpayer to the Department of Revenue in the event that the director should conclude that the hospitals retain their right to be left off the tax rolls. See NW Medical Lab. v. Good Samaritan Hospital, 309 Or 262, 786 P2d 718 (1990) (so holding). The hospitals point out that such an appeal is costly and may take years to resolve. Whether or not those arguments are well taken, they fall within the province of the legislature and not this court.

The hospitals also point out that they moved to intervene as soon as practicable upon learning of the mandamus proceeding. We agree that the promptness of the hospitals’ attempt to intervene is a relevant factor for a court to consider in assessing whether to exercise discretion to allow a party to intervene in a mandamus proceeding. We also are sympathetic to the fact that the hospitals did not become aware of the mandamus proceeding until after the alternative writ had been issued. When a mandamus proceeding arises from a “judicial or administrative proceeding,” a relator must serve a copy of the mandamus petition “on all parties” to the judicial or administrative proceeding. ORS 34.130(2). Had the hospitals been served with a copy of the mandamus petition, they could have moved to intervene before the return date on the alternative writ. In that event, the Tax Court would have been required to allow the hospitals to intervene as a matter of right. ORS 34.130(4).

*323However, we review here only for abuse of discretion. Although the circumstances could have supported a decision to allow the hospitals to intervene, the hospitals have cited no rule of law — nor are we aware of one — that required the court to allow intervention. Thus, the Tax Court faced a classic example of a situation in which it legally could have ruled either way. Under the circumstances of this case, we do not find that the Tax Court’s denial of the motions to intervene amounted to an abuse of discretion. We hold that the Tax Court did not abuse its discretion in denying the hospitals’ motions to intervene in this mandamus proceeding.

The order of the Tax Court is affirmed.