dissenting. I agree with the majority’s conclusion that neither the Waitsfield town plan nor its zoning ordinance provides sufficient contextual guidance to determine whether the Town intended to apply the prohibition against “steep slope” development to *137“severe slopes” (i.e., slopes having grades between 15 and 25 percent) or only “extreme” slopes (i.e., slopes having grades over 25 percent). I concur, therefore, in the determination that the Environmental Board erred in concluding that the proposed subdivision violated the “steep slope” provision of the town plan.
I do not agree with the majority’s conclusion that the Board erred in determining that the road improvements necessary for vehicular access to a proposed five-lot subdivision in the Town’s Forest Reserve District would violate the town plan’s stated objective of “[m]aintain[ing] the current status of all class four Town Highways to promote their use for walking, bicycling and horseback riding.” As the record makes clear, the Board’s decision was consistent with the plan, the zoning ordinance, and traditional usage within the Forest Reserve District, which together evinced a clear policy of allowing limited residential development and seasonal homes, but discouraging multiunit subdevelopments of the kind at issue here. Therefore, I would affirm the decision of the Board denying landowners’ application for an Act 250 permit.
I.
This case was tried and appealed as a straightforward issue of textual interpretation. In connection with their proposed subdivision project, landowners planned to upgrade approximately 2400 feet of Bowen Road, an unmaintained class four road, through substantial widening and drainage improvements. The issue before the Board was whether the proposed upgrade was consistent with the town plan, one objective of which was to “Maintain the current status of all class four Town Highways to promote their use for walking, bicycling and horseback riding.” Landowners argued that “maintain the current status” does not mean “maintain the current physical condition,” but rather maintain the class four “legal classification.” In support of their contention, landowners cited several cases and statutes which appear to employ the term “status” as the functional equivalent of legal classification, and two other sections of the town plan which arguably provided contextual support for their position.
The Town argued, and the Board found, that the meaning and purpose of the restriction was to restrict the physical improvement of class four roads. Reading the plan as a whole made plain that the goal of the restriction was not merely to maintain Bowen Road’s “legal” status, but to preserve the character of the Forest Reserve District. The plan cautioned that improving the few unmaintained roads in the *138district could significantly alter its unspoiled character by creating pressure for substantial development, and that existing recreational opportunities such as horseback riding, hiking, bicycling, and hunting “could be diminished through increased automobile access.”
The majority argues, however, that regardless of the Board’s conclusion, the restriction on upgrades of class four roads constitutes little more than a “nonregulatory abstraction” of the kind criticized in In re Molgano, 163 Vt. 25, 31, 653 A.2d 772, 775 (1994). The argument-was not advanced by landowners at trial or in their appellate briefs. The reason is clear. The provision restricting upgrades on class four roads is concrete and precise. The Town’s objective is to maintain the existing condition of class four roads, particularly in the Forest Reserve District, in order to limit vehicular access and development, and to preserve existing recreational opportunities and open space. There is nothing abstract about this policy and objective.
This Court has uniformly applied a deferential standard to decisions of the Environmental Board. “We . . . defer to the Environmental Board’s conclusions of law if they are rationally derived from the correct.interpretation of law and findings of fact based on substantial evidence.” In re Commercial Airfield, 170 Vt. 595, 595, 752 A.2d 13, 14 (2000) (mem.). Read as a whole, the town plan clearly supports the Board’s conclusion that the objective of the restriction on class-four road upgrades was to preserve the physical condition of the roads in the Forest Reserve District in order to inhibit vehicular access, limit development, preserve the unspoiled character of the district, and enhance recreational opportunities. Maintaining the legal classification of the road while transforming its physical characteristics to accommodate substantial vehicular traffic plainly undermines the purpose of the restriction. Thus, the Board’s conclusion that the proposed upgrade was inconsistent with the town plan was amply supported, and should be affirmed. See In re MBL Assocs., 166 Vt. 606, 607-08,693 A.2d 698, 701 (1997) (mem.) (affirming Board’s interpretation of regional plan to conclude that proposed subdivision was consistent with plan).
H.
Notably absent from landowners’ pleadings and briefing was any assertion that the Town’s initial decision to grant a subdivision permit for the project somehow provided authoritative evidence of the Town’s underlying legislative intent with respect to the meaning of “status.” It is not difficult to understand this omission. Although this Court has recognized that municipal actions may provide some indication as to *139the meaning of local zoning regulations, see In re Duncan, 155 Vt. 402, 408, 584 A.2d 1140, 1144 (1990), the test is whether there has been “a consistent interpretation of the provision by the local officials who administer it.” In re Vermont Nat’l Bank, 157 Vt. 306, 313, 597 A.2d 317, 320 (1991) (emphasis added); see also In re Chatelain, 164 Vt. 597, 598, 664 A.2d 269, 270 (1995) (mem.) (relying on Vermont National Bank to hold that “there is ‘no indication of a consistent interpretation of the [zoning] provision’ to which we must give deference”).
The “consistent interpretation” requirement reflects the general rule that courts may defer to administrative interpretations of zoning ordinances where the record demonstrates a consistent application of the ordinance over time. The principle was cogently summarized in Sinelli v. Birmingham Board of Zoning Appeals, 408 N.W.2d 412 (Mich. Ct. App. 1987), as follows: “In cases of ambiguity in a municipal zoning ordinance, the past practical construction over an extensive period by the officer or administrative agency charged with its administration is to be accorded great weight in determining its meaning.” Id. at 414 (quoting 82 Am. Jur. 2d, Zoning & Planning § 66) (emphasis added); see also Clark v. Town Council, 144 A.2d 327, 332 (Conn. 1958) (“The practical construction placed over the years upon ambiguous language in legislation by those charged with its administration becomes weighty evidence of what the law is.”) (emphasis added); Exxon Corp. v. Board of Standards, 515 N.Y.S.2d 768, 773 (App. Div. 1987) (“courts should give due consideration to an agency’s practical construction of a statute over a period of time”) (emphasis added).
Without so much as acknowledging the applicable case law, much less the fact that the argument was never raised, the majority here conclude that the Town’s actions in issuing a subdivision permit and subsequent work permit represented a persuasive “interpretation of the plan by the municipal bod[y] responsible for its implementation and enforcement.” 172 Vt. at 133, 772 A.2d at 142. Indeed, the majority characterize the Town’s actions as the “most important” source of the provision’s meaning. Id. In so concluding, the majority point to nothing in the record evidence demonstrating a consistent interpretation of the provision over time by the local officials who administer it. They cite no evidence of prior instances in which the Town has approved similar class-four road improvements for developments in the Forest Reserve District. Cf. Sinelli, 408 N.W.2d at 414 (noting that town had demonstrated consistent interpretation of its ordinance through affidavit of building official “listing several specific instances” in which *140town had taken similar actions). Accordingly, the majority’s reliance on the Town’s decision to issue two permits, in this one matter, as persuasive evidence of legislative intent, is entirely misplaced.
It bears mention, additionally, that the Town’s actions here were hardly consistent. Although the majority notes that a subdivision permit with nineteen conditions attached ultimately did issue, it does not indicate that landowners’ initial application was denied. Landowners later submitted another application, only to withdraw it voluntarily in the face of substantial concerns expressed by the Town planning commission. A third application was eventually approved, after extensive discussion and negotiations, by a five-to-three vote of the planning commission. Thus, the majority’s assertion that the discrepant decisions of local officials in this case “strongly supports landowners’ position,” 172 Vt. at 133, 772 A.2d at 142, and is, therefore, the most significant evidence of the Town plan’s meaning, will surprise the landowners as well as the Town.
Nor, finally, is it accurate to maintain — as the majority does — that this is an argument “that no deference should be given to the interpretation of the town bodies that administer the plan.” Id. at 135 n.6, 772 A.2d at 143 n.6. Where an agency’s interpretation of a statute would clarify the issue when “[t]he statute itself obviously does not speak with any clarity to the situation,” reliance on the agency’s interpretation is appropriate. Hogan v. Department of Soc. & Rehab. Servs., 168 Vt. 615, 617, 727 A.2d 1242, 1244 (1998) (mem.).
Here, however, the majority is adopting an interpretation of the Town plan in direct opposition to the Town’s interpretation in this lawsuit, and then faulting the dissent for not giving deference to the Town. It is deference to the Town’s interpretation — not the majority’s — that is required. To the extent the Town’s application of the class-four road provision may be said not to “speak with any clarity to the situation,” id., the appropriate recourse to an administrative interpretation is to the construction of the Town plan asserted by the Town and adopted by the Environmental Board in this case.
III.
The majority further asserts that the Board’s interpretation of the plan effectively “ban[s]” all development within the Forest Reserve District, contrary to the zoning ordinance. 172 Vt. at 134, 772 A.2d at 143. This is also an argument not found in landowners’ briefs. The reason, of course, is that the Town has never prohibited residential development within the Forest Reserve District consistent with the *141preservation of existing resources and infrastructure. As various Town officers explained below, the Town’s objective is to restrict residential land subdivisions of large forest parcels that will require substantial upgrades and services, and that might impact the fragile resources and character of the district. These kinds of projects are to be distinguished from more limited residential development of single dwellings for seasonal use that do not require such extensive improvements.
Much of the majority’s rationale appears to be rooted in unspecified suspicions about the Town’s motives. See id. at 136, 772 A.2d at 144 (“For whatever reasons, the Town is attempting, through Act 250, to undo its own regulatory decisions . . . .”). I acknowledge that landowners’ lengthy struggle to obtain permit approval for a controversial development has prompted varied attempts to accommodate the landowners and the Town, but I do not — as the majority does — conclude that the Town is illegitimately attempting to “retroactively apply its new zoning regime to a development to which it is not applicable.” Id. The very “regulatory” decisions which the majority accuses the Town of attempting to “undo” contained specific language preserving the Town’s right to object to landowners’ project. The permit for the Bowen Road improvements stated that the selectboard was not “making either an express or implied statement regarding the appropriateness of [the] proposed five-lot subdivision; nor does it waive any of its rights to represent the interests of the Town in any proceedings, legal or otherwise, relative to this matter.” The subdivision permit itself contained nineteen specific conditions, and Town officials indicated at trial that their position was grounded, in part, upon indications that landowners did not intend to comply with the conditions.
The majority accurately notes that the purpose of Act 250 “is not to supersede local regulation” of local development. Id. at 135, 772 A.2d at 143. Here, the Environmental Board was careful not to do so. The majority was not. I respectfully dissent.